Rusty Sidearm
How to Unlock: You start with this while playing The Huntress.

Marine Sidearm
How to Unlock: You start with this while playing The Marine.

Rouge Special
How to Unlock: You start with this while playing The Pilot.

Budget Revolver
How to Unlock: You start with this while playing The Convict.

Dart Gun
How to Unlock: Start co-op mode and select The Cultist as your 2nd player. The 2nd player starts with this while playing The Cultist.

Robot's Right Hand
How to Unlock: You start with this while playing The Robot.

Blasphemy
Tier: B
How to Unlock: Kill the Dragun with The Bullet. You start with this while playing The Bullet.

Casey
Tier: D
How to Unlock: Purchased from Doug for 12 Hegemony credits.

Pea Shooter
Tier: D
How to Unlock: Complete Sir Manuel's tutorial.

38 Special
Tier: D
How to Unlock: Unlocked from the start.

Derringer
Tier: D
How to Unlock: Unlocked from the start.

Slinger
How to Unlock: You start with this while playing The Gunslinger.

Trank Gun
Tier: C
How to Unlock: Unlocked from the start.

Unfinished Gun
Tier: D
How to Unlock: Unlocked from the start.

Elimantaler
Tier: S
How to Unlock: Opening Resourceful Rat chests from keys you gain during his 3rd phase.

Bullet
Tier: C
How to Unlock: Unlocked from the start.

Shell
Tier: B
How to Unlock: Unlocked from the start.

Hyper Light Blaster
Tier: B
How to Unlock: Purchased from Doug for 22 Hegemony credits.

Boxing Glove
Tier: C
How to Unlock: Defeat the Resourceful Rat's first 2 phases.

Makarov
Tier: D
How to Unlock: Unlocked from the start.

M1911
Tier: C
How to Unlock: Unlocked from the start.

Magnum
Tier: B
How to Unlock: Unlocked from the start.

Colt 1851
Tier: C
How to Unlock: Unlocked from the start.

SAA
Tier: B
How to Unlock: Unlocked from the start.

Cold 45
Tier: B
How to Unlock: Use a green Gun Muncher 10 times.

Polaris
Tier: B
How to Unlock: Complete the 4th Chamber 20 times.

Jolter
Tier: B
How to Unlock: Unlocked from the start.

Dungeon Eagle
Tier: C
How to Unlock: Unlocked from the start.

Grey Mauser
Tier: B
How to Unlock: Complete the last Grey Mauser quest.

Vorpal Gun
Tier: B
How to Unlock: Purchased from Doug for 20 Hegemony credits.

High Kaliber
Tier: A
How to Unlock: Unlocked from the start.

Shellegun
Tier: B
How to Unlock: Complete the Grey Mauser's 12th quest.

Dueling Pistol
Tier: D
How to Unlock: Unlocked from the start.

AU Gun
Tier: S
How to Unlock: Unlocked from the start.

Big Iron
Tier: B
How to Unlock: Unlocked from the start.

Composite Gun
Tier: S
How to Unlock: Unlocked from the start.

Flare Gun
Tier: D
How to Unlock: Unlocked from the start.

Smiley's Revolver
Tier: B
How to Unlock: Unlocked from the start.

Shade's Revolver
Tier: C
How to Unlock: Unlocked from the start.

Knight's Gun
Tier: A
How to Unlock: Purchased from Doug for 28 Hegemony credits.

GuNNER
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Regular Shotgun
Tier: D
How to Unlock: Unlocked from the start.

Big Shotgun
Tier: A
How to Unlock: Purshed from Doug for 26 Hegemony credits.

Old Goldie
Tier: A
How to Unlock: Unlocked from the start.

Sawed-Off
Tier: D
How to Unlock: You start with this as The Convict.

Winchester
Tier: C
How to Unlock: Unlocked from the start.

Rattler
Tier: B
How to Unlock: Complete the Grey Mauser's 9th quest.

Bubble Blaster
Tier: C
How to Unlock: Unlocked from the start.

Elephant Gun
Tier: C
How to Unlock: Complete the Grey Mauser's 2nd quest.

Tangler
Tier: C
How to Unlock: Purchased from Ox & Cadence for 10 Hegemony credits.

Void Shotgun
Tier: B
How to Unlock: Unlocked from the start.

Mass Shotgun
Tier: B
How to Unlock: Purchased from Ox & Cadence for 9 Hegemony credits.

Shotgun Full of Hate
Tier: A
How to Unlock: Unlocked from the start.

Shotgun Full of Love
Tier: A
How to Unlock: Unlocked from the start.

Shotgrub
Tier: C
How to Unlock: Unlocked from the start.

Gilded Hydra
Tier: S
How to Unlock: Kill The Convict's, Marine's, Pilot's, and Huntress' pasts.

Blunderbuss
Tier: D
How to Unlock: Unlocked from the start.

Pulse Cannon
Tier: C
How to Unlock: Unlocked from the start.

Siren
Tier: C
How to Unlock: Unlocked from the start.

Zilla Shotgun
Tier: A
How to Unlock: Unlocked from the start.

Ice Breaker
Tier: B
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

The Membrane
Tier: C
How to Unlock: Purchased from Professor Goopton for 10 Hegemony credits.

The Huntsman
Tier: C
How to Unlock: Unlocked from the start.

Blooper
Tier: B
How to Unlock: Unlocked from the start.

JK-47
Tier: C
How to Unlock: Unlocked from the start.

Bow
Tier: C
How to Unlock: Unlocked from the start.

Charmed Bow
Tier: B
How to Unlock: Unlocked from the start.

Crossbow
Tier: D
How to Unlock: You start with this as The Huntress.

Sticky Crossbow
Tier: C
How to Unlock: Unlocked from the start.

Shotbow
Tier: B
How to Unlock: Unlocked from the start.

Triple Crossbow
Tier: C
How to Unlock: Unlocked from the start.

Crescent Crossbow
Tier: A
How to Unlock: Unlocked from the start.

Gunbow
Tier: A
How to Unlock: Unlocked from the start.

Klobbe
Tier: D
How to Unlock: Unlocked from the start.

Machine Pistol
Tier: D
How to Unlock: Unlocked from the start.

Thompson Sub-Machinegun
Tier: C
How to Unlock: Purchased from Ox & Cadence for 1 Hegemony credit.

AK-47
Tier: B
How to Unlock: Unlocked from the start.

STRAFE GUN
Tier: S
How to Unlock: Purchased from Doug for 26 Hegemony credits.

AKEY-47
Tier: S
How to Unlock: Complete the Chamber 5 elevator shortcut.

Stone Dome
Tier: B
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Crown of Guns
Tier: C
How to Unlock: Unlocked from the start.

M16
Tier: A
How to Unlock: Purchased from Trorc for 5 Hegemony credits.

Combined Rifle
Tier: B
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Zorgun
Tier: A
How to Unlock: Unlocked from the start.

The Fat Line
Tier: B
How to Unlock: Kill the Dragun with The Paradox.

Mr. Accretion Jr.
Tier: B
How to Unlock: Unlocked from the start.

VertebreAK-47
Tier: B
How to Unlock: Unlocked from the start.

Balloon Gun
Tier: C
How to Unlock: Unlocked from the start.

MAC-10
Tier: C
How to Unlock: Unlocked from the start.

Triple Gun
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Heck Blaster
Tier: B
How to Unlock: Unlocked from the start.

Patriot
Tier: S
How to Unlock: Purchased from Trorc for 12 Hegemony credits.

AC-15
Tier: B
How to Unlock: Unlocked from the start.

Vulcan Cannon
Tier: S
How to Unlock: Unlocked from the start.

Plague Pistol
Tier: D
How to Unlock: Purchased from Professor Goopton for 6 Hegemony credits.

Gungine
Tier: S
How to Unlock: Complete the Chamber 4 elevator shortcut.

The Predator
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Dragunfire
Tier: A
How to Unlock: Kill the Dragun.

Sniper Rifle
Tier: C
How to Unlock: Unlocked from the start.

AWP
Tier: A
How to Unlock: Purchased from Trorc for 10 Hegemony credits.

M1
Tier: C
How to Unlock: Unlocked from the start.

Winchester Rifle
Tier: D
How to Unlock: Unlocked from the start.

Corsair
Tier: C
How to Unlock: Unlocked from the start.

Railgun
Tier: S
How to Unlock: Purchased from Ox & Cadence for 30 Hegemony credits.

Prototype Railgun
Tier: A
How to Unlock: Unlocked from the start. Not to be confused with the Railgun.

Void Marshal
Tier: B
How to Unlock: Unlocked from the start.

Deck4rd
Tier: A
How to Unlock: Unlocked from the start.

The Judge
Tier: B
How to Unlock: Unlocked from the start.

Mourning Star
Tier: S
How to Unlock: Purchased from Doug for 22 Hegemony credits.

Alien Sidearm
Tier: D
How to Unlock: Unlocked from the start.

RUBE-ADYNE Prototype
Tier: B
How to Unlock: Unlocked from the start.

RUBE-ADYNE MK.II
Tier: A
How to Unlock: Unlocked from the start.

Rubenstein's Monster
How to Unlock: Pick up both RUBE-ADYNE Prototype and RUBE-ADYNE MK; behaves differently from a synergy upgrade for... reasons. Not needed to complete the Ammonomicon.

Chamber Gun
Tier: C
How to Unlock: Visit every Chamber and secret floor in the Gungeon.

Gunderfury
Tier: A
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Mine Cutter
Tier: B
How to Unlock: Complete the 3rd Chamber 30 times.

Void Core Assault Rifle
Tier: B
How to Unlock: Unlocked from the start.

Flash Ray
Tier: D
How to Unlock: Purchased from Ox & Cadence for 6 Hegemony credits.

Wind Up Gun
Tier: D
How to Unlock: Unlocked from the start.

H4mmer
Tier: B
How to Unlock: Unlocked from the start.

Snakemaker
Tier: A
How to Unlock: Complete the Grey Mauser's 10th quest.

Turbo-Gun
Tier: C
How to Unlock: Unlocked from the start.

Hegemony Carbine
Tier: C
How to Unlock: Purchased from Ox & Cadence for 3 Hegemony credits.

Screecher
Tier: C
How to Unlock: Unlocked from the start.

Laser Lotus
Tier: A
How to Unlock: Unlocked from the start.

Hegemony Rifle
Tier: B
How to Unlock: Unlocked from the start.

Fightsabre
Tier: S
How to Unlock: Unlocked from the start.

Helix
Tier: C
How to Unlock: Unlocked from the start.

Laser Rifle
Tier: C
How to Unlock: Unlocked from the start.

Crestfaller
Tier: C
How to Unlock: Unlocked from the start.

Rad Gun
Tier: B
How to Unlock: Unlocked from the start.

Thunderclap
Tier: A
How to Unlock: Unlocked from the start.

Charge Shot
Tier: B
How to Unlock: Unlocked from the start.

Dark Maker
Tier: S
How to Unlock: Unlocked from the start.

Particulator
Tier: S
How to Unlock: Unlocked from the start.

The Emperor
Tier: A
How to Unlock: Unlocked from the start.

RPG
Tier: B
How to Unlock: Purchased from Ox & Cadence for 5 Hegemony credits.

Grenade Launcher
Tier: B
How to Unlock: Unlocked from the start.

Stinger
Tier: B
How to Unlock: Unlocked from the start.

The Exotic
Tier: A
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Com4nd0
Tier: B
How to Unlock: Purchased from Trorc for 8 Hegemony credits.

RC Rocket
Tier: A
How to Unlock: Purchased from Trorc for 15 Hegemony credits.

Yari Launcher
Tier: S
How to Unlock: Purchased from Ox & Cadence for 25 Hegemony credits.

Lil' Bomber
Tier: D
How to Unlock: Unlocked from the start.

Grasschopper
Tier: A
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Void Core Cannon
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Bundle of Wands
Tier: C
How to Unlock: Complete the Grey Mauser's 4th quest.

Staff of Firepower
Tier: A
How to Unlock: Complete the 2nd Chamber 40 times.

Witch Pistol
Tier: C
How to Unlock: Unlocked from the start.

Hexagun
Tier: B
How to Unlock: Unlocked from the start.

Phoenix
Tier: D
How to Unlock: Unlocked from the start.

Magic Lamp
Tier: B
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Teapot
Tier: C
How to Unlock: Unlocked from the start.

Gunslinger's Ashes
Tier: C
How to Unlock: Use a red Gun Muncher 10 times. Red munchers are much rarer and require a varying amount of weapons to activate. One red muncher is always found in a secret room on the 6th Chambers.

Luxin Cannon
Tier: C
How to Unlock: Unlocked from the start.

Gunther
Tier: S
How to Unlock: Unlock the Sorceress and activate her blessing. Kill the Dragun with the blessing to unlock this gun.

Unicorn Horn
Tier: A
How to Unlock: Complete the Grey Mauser's 3rd quest.

Cobalt Hammer
Tier: A
How to Unlock: Complete the 5th Chamber 10 times.

Frost Giant
Tier: B
How to Unlock: Kill the 4th Chamber boss without getting hit.

Bullet Bore
Tier:
How to Unlock: Purchased from Ox & Cadence for 14 Hegemony credits.

Cat Claw
Tier:
How to Unlock: Complete the Grey Mauser's 11th quest.

Megahand
Tier:
How to Unlock: Unlocked from the start.

Demon Head
Tier:
How to Unlock: Unlocked from the start.

The Heroine
Tier:
How to Unlock: Purchased from Ox & Cadence for 13 Hegemony credits.

Mutation
Tier: B
How to Unlock: Create a gun using a Gun Muncher of any kind 10 times.

Flame Hand
Tier: B
How to Unlock: Unlocked from the start.

Sunlight Javelin
Tier: B
How to Unlock: Reach The Cultist's past OR kill the Dragun with a companion.

Machine Fist
Tier: A
How to Unlock: Unlocked from the start.

Robot's Left Hand
Tier: A
How to Unlock: Kill The Robot's past.

Snowballer
Tier: D
How to Unlock: Unlocked from the start.

Super Meat Gun
Tier: A
How to Unlock: Unlocked from the start.

Anvillian
Tier: C
How to Unlock: Unlocked from the start.

Fossilized Gun
Tier: D
How to Unlock: Purchased from Professor Goopton for 12 Hegemony credits.

Gamma Ray
Tier: C
How to Unlock: Purchased from Ox & Cadence for 2 Hegemony credits.

Freeze Ray
Tier: A
How to Unlock: Purchased from Ox & Cadence for 7 Hegemony credits.

Science Cannon
Tier: B
How to Unlock: Purchased from Ox & Cadence for 6 Hegemony credits.

Disintegrator
Tier: S
How to Unlock: Unlocked from the start.

Proton Backpack
Tier: B
How to Unlock: Unlocked from the start.

Mega Douser
Tier: D
How to Unlock: Unlocked from the start.

Plunger
Tier: C
How to Unlock: Purchased from Professor Goopton for 7 Hegemony credits.

Raiden Coil
Tier: A
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Moonscraper
Tier:
How to Unlock: Unlocked from the start.

Barrel
Tier: C
How to Unlock: Unlocked from the start.

Trick Gun
Tier: C
How to Unlock: Unlocked from the start.

Mailbox
Tier: D
How to Unlock: Purchased from Ox & Cadence for 5 Hegemony credits.

Nail Gun
Tier: D
How to Unlock: Unlocked from the start.

Light Gun
Tier: B
How to Unlock: Unlocked from the start.

Dueling Laser
Tier: B
How to Unlock: Purchased from Doug for 20 Hegemony credits.

Wood Beam
Tier: B
How to Unlock: Unlock the Vampire and give hearts to them 3 times.

Mahoguny
Tier: C
How to Unlock: Unlocked from the start.

The Scrambler
Tier: C
How to Unlock: Unlocked from the start.

Trashcannon
Tier: C
How to Unlock: Enter the Oubliette from Chamber 1.

Glacier
Tier: A
How to Unlock: Unlocked from the start.

Origuni
Tier: C
How to Unlock: Purchased from Ox & cadence for 6 Hegemony credits.

The Kiln
Tier: C
How to Unlock: Unlocked from the start.

Skull Spitter
Tier: C
How to Unlock: Unlocked from the start.

Buzzkill
Tier: C
How to Unlock: Unlocked from the start.

Tear Jerker
Tier: C
How to Unlock: Unlocked from the start.

Starpew
Tier: A
How to Unlock: Purchased from Doug for 20 Hegemony credits.

Eye of the Beholster
Tier: B
How to Unlock: Unlocked from the start.

Molotov Launcher
Tier: C
How to Unlock: Unlocked from the start.

Glass Cannon
Tier: C
How to Unlock: Unlocked from the start.

Shock Rifle
Tier: B
How to Unlock: Unlocked from the start.

Bait Launcher
Tier: C
How to Unlock: Go into your gameplay options and turn on something called "Beast Mode" and kill the Dragun with this enabled. As far as I can tell, Beast Mode changes nothing.

Brick Breaker
Tier: C
How to Unlock: Complete the 1st Chamber 50 times.

Betrayer's Shield
Tier: B
How to Unlock: Kill Blockner in Chamber 3 for the first time.

Lower Case r
Tier: D
How to Unlock: Unlocked from the start.

Excaliber
Tier: B
How to Unlock: Unlock The Lost Adventurer and complete a map for him 5 times.

Face Melter
Tier: B
How to Unlock: Purchased from Ox & Cadence for 10 Hegemony credits.

Really Special Lute
Tier: C
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Trident
Tier: A
How to Unlock: Unlocked from the start.

Kruller Glaive
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Abyssal Tentacle
Tier: A
How to Unlock: Purchased from Professor Goopton for 15 Hegemony credits.

Quad Laser
Tier: C
How to Unlock: Unlocked from the start.

Tetrominator
Tier: B
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Pitchfork
Tier: C
How to Unlock: Unlocked from the start.

Evolver
Tier: C
How to Unlock: Purchased from Professor Goopton for 35 Hegemony credits.

Gungeon Ant
Tier: C
How to Unlock: Unlocked from the start.

Life Orb
Tier: A
How to Unlock: Use the Blood Shrine twice.

Alien Engine
Tier: B
How to Unlock: Unlocked from the start.

Microtransaction Gun
Tier: A
How to Unlock: Purchased from Ox & Cadence for 100 Hegemony credits OR buy the proper EtG DLC for $1 USD.

Poxcannon
Tier: C
How to Unlock: Unlocked from the start.

T-Shirt Cannon
Tier: D
How to Unlock: Unlocked from the start.

Banana
Tier: C
How to Unlock: Unlocked from the start.

Bee Hive
Tier: B
How to Unlock: Unlocked from the start.

Silencer
Tier: C
How to Unlock: Unlocked from the start.

Camera
Tier: C
How to Unlock: Unlocked from the start.

Directional Pad
Tier: B
How to Unlock: Unlocked from the start.

3rd Party Controller
Tier: A
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Gunzheng
Tier: B
How to Unlock: Complete the Grey Mauser's 14th quest.

Sling
Tier: D
How to Unlock: Complete the Grey Mauser's 1st quest.

Cactus
Tier: C
How to Unlock: Unlocked from the start.

Black Hole Gun
Tier: A
How to Unlock: Purchased from Ox & Cadence for 20 Hegemony credits.

BSG
Tier: S
How to Unlock: Unlocked from the start.

Compressed Air Tank
Tier: A
How to Unlock: Complete the Grey Mauser's 8th quest.

Serious Cannon
Tier: A
How to Unlock: Unlocked from the start.

Makeshift Cannon
Tier: S
How to Unlock: Complete the Grey Mauser's 13th quest.

Devolver
Tier: C
How to Unlock: Purchased from Doug for 10 Hegemony credits.

Finished Gun
Tier D/S
How to Unlock: Fill in every single other entry in the Ammonomicon (except for the items Lies, Rubenstein's Monster, High Dragunfire, and Number 2), replaces Unfinished Gun.

Master Round I
How to Unlock: Doesn't need to be unlocked but can only be obtained by beating the Chamber 1 boss without taking a hit.

Master Round II
How to Unlock: Doesn't need to be unlocked but can only be obtained by beating the Chamber 2 boss without taking a hit.

Master Round III
How to Unlock: Doesn't need to be unlocked but can only be obtained by beating the Chamber 3 boss without taking a hit.

Master Round IV
How to Unlock: Doesn't need to be unlocked but can only be obtained by beating the Chamber 4 boss without taking a hit.

Master Round V
How to Unlock: Doesn't need to be unlocked but can only be obtained by beating the Dragun without taking a hit.

Prime Primer
How to Unlock: Doesn't need to be unlocked but can be bought in the Chamber 2 shop for 110 casings and given to the Blacksmith on Chamber 5.

Arcane Gunpowder
How to Unlock: Doesn't need to be unlocked but can be found on the Minecart Maze in Chamber 3 and given to the Blacksmith on Chamber 5.

Planar Lead
How to Unlock: Doesn't need to be unlocked but can be found after the invisible bridge and given to the Blacksmith on Chamber 5.

Obsidian Shell Casing
How to Unlock: Doesn't need to be unlocked and is found by destroying the Dragun's skull after killing it in Chamber 5 and is given to the Blacksmith in the same chamber.

Blank
How to Unlock: Cannot be unlocked. You start with 2 each floor and more can be found as room clear reward, in secret rooms, and in the shop.

Meatbun
Rank: D
How to Unlock: Unlocked from the start.

Medkit
Rank: C
How to Unlock: Unlocked from the start.

Ration
Rank: C
How to Unlock: Unlocked from the start.

Orange
Rank: B
How to Unlock: Unlocked from the start.

Friendship Cookie
How to Unlock: You start with this while playing The Cultist in co-op mode.

Bottle
Rank: D
How to Unlock: Kill the Shadow Magician.

Bomb
Rank: D
How to Unlock: Unlocked from the start.

Ice Bomb
Rank: D
How to Unlock: Unlocked from the start.

Chaff Grenade
Rank: C
How to Unlock: Purchased from Trorc for 13 Hegemony credits.

Proximity Mine
Rank: D
How to Unlock: Unlocked from the start.

Cluster Mine
Rank: C
How to Unlock: Purchased from Trorc for 3 Hegemony credits.

C4
Rank: D
How to Unlock: Unlocked from the start.

Weird Egg
Rank: D
How to Unlock: Reach the Resourceful Rat's Lair.

Molotov
Rank: D
How to Unlock: You start with this while playing The Convict.

Air Strike
Rank: B
How to Unlock: Purchased from Trorc for 6 Hegemony credits.

Napalm Strike
Rank: C
How to Unlock: Purchased from Professor Goopton for 18 Hegemony credits.

Big Boy
Rank: B
How to Unlock: Purchased from Trorc for 20 Hegemony credits.

Roll Bomb
Rank: C
How to Unlock: Purchased from Doug for 12 Hegemony credits.

iBomb Companion App
Rank: C
How to Unlock: Unlocked from the start.

Supply Drop
Rank: D
How to Unlock: Occasionally found as a room clear reward. You start with this while playing The Marine.

Ammo Synthesizer
Rank: D
How to Unlock: Unlocked from the start.

Heart Synthesizer
Rank: A
How to Unlock: Unlocked from the start.

Armor Synthesizer
Rank: A
How to Unlock: Unlocked from the start.

Master of Unlocking
Rank: B
How to Unlock: Unlocked from the start.

Utility Belt
Rank: C
How to Unlock: Unlocked from the start.

Macho Brace
Rank: C
How to Unlock: Unlock Synergrace and buy Synergy Chests from her 3 times.

Hidden Compartment
How to Unlock: Cannot be unlocked. You start with this while playing The Pilot.

Backpack
Rank: D
How to Unlock: Unlocked from the start.

Loot Bag
Rank: C
How to Unlock: Steal it from a shop using some sort of invisibility or time stopping item.

Drill
Rank: D
How to Unlock: Steal it from a shop using some sort of invisibility or time stopping item.

Clown Mask
Rank: B
How to Unlock: Steal it from a shop using some sort of invisibility or time stopping item.

Scope
Rank: D
How to Unlock: Unlocked from the start.

Scouter
Rank: C
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Laser Sight
Rank: C
How to Unlock: Unlocked from the start.

Ammo Belt
Rank: D
How to Unlock: Unlocked from the start.

Bullet Time
Rank: D
How to Unlock: Unlocked from the start.

Aged Bell
Rank: A
How to Unlock: Unlocked from the start.

Singularity
Rank: C
How to Unlock: Purchased for Ox & Cadence for 12 Hegemony credits.

Decoy
Rank: D
How to Unlock: Unlocked from the start.

Shadow Clone
Rank: D
How to Unlock: Unlocked from the start.

Explosive Decoy
Rank: C
How to Unlock: Unlocked from the start.

Melted Rock
Rank: C
How to Unlock: Unlocked from the start.

Trusty Lockpicks
Rank: D
How to Unlock: Kill The Pilot's past.

Smoke Bomb
Rank: C
How to Unlock: Unlocked from the start.

Box
Rank: A
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Fortune's Favor
Rank: B
How to Unlock: Unlocked from the start.

Jar of Bees
Rank: C
How to Unlock: Unlocked from the start.

Potion of Lead Skin
Rank: D
How to Unlock: Unlocked from the start.

Double Vision
Rank: D
How to Unlock: Unlocked from the start.

Chest Teleporter
Rank: A
How to Unlock: Kill The Robot's past.

Relodestone
Rank: S
How to Unlock: Unlocked from the start.

Poison Vial
Rank: D
How to Unlock: Unlocked from the start.

Potion of Gun Friendship
Rank: D
How to Unlock: Unlocked from the start.

Portable Turret
Rank: B
How to Unlock: Purchased from Ox & Cadence for 12 Hegemony credits.

Knife Shield
Rank: D
How to Unlock: Unlocked from the start.

Grappling Hook
Rank: D
How to Unlock: Unlocked from the start.

Stuffed Star
Rank: B
How to Unlock: Unlocked from the start.

Boomerang
Rank: B
How to Unlock: Unlocked from the start.

Shield of the Maiden
Rank: C
How to Unlock: Kill the 1st Chamber boss without getting hit.

Crisis Stone
Rank: A
How to Unlock: Unlock Tonic the Sled Dog and activate his Turbo Mode. Kill the High Dragun with this mode on to unlock this item.

Portable Table Device
Rank: D
How to Unlock: Dodge roll into tables to slide across them 50 times.

Daruma
Rank: B
How to Unlock: Find a Gripmaster and get grabbed by it.

Partially-Eaten Cheese
Rank: A
How to Unlock: Opening Resourceful Rat chests from keys you gain during his 3rd phase.

+1 Bullets
Rank: C
How to Unlock: Purchased from Ox & Cadence for 6 Hegemony credits.

Rocket-Powered Bullets
Rank: B
How to Unlock: Purchased from Ox & Cadence for 4 Hegemony credits.

Shock Rounds
Rank: A
How to Unlock: Unlocked from the start.

Devolver Rounds
Rank: B
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Vorpal Bullets
Rank: A
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Katana Bullets
Rank: C
How to Unlock: Kill the boss at the end of the R&G Dept.

Hungry Bullets
Rank: A
How to Unlock: Find a Tarnisher and get swallowed up by it.

Heavy Bullets
Rank: C
How to Unlock: Unlocked from the start.

Bouncy Bullets
Rank: C
How to Unlock: Unlocked from the start.

Explosive Rounds
Rank: A
How to Unlock: Unlocked from the start.

Ghost Bullets
Rank: C
How to Unlock: Unlocked from the start.

Alpha Bullets
Rank: A
How to Unlock: Assemble the pieces for the Bullet That Can Kill The Past.

Omega Bullets
Rank: A
How to Unlock: Assemble the pieces for the Bullet That Can Kill The Past.

Scattershot
Rank: B
How to Unlock: Unlocked from the start.

Irradiated Lead
Rank: B
How to Unlock: Unlocked from the start.

Hot Lead
Rank: B
How to Unlock: Purchased from Ox & Cadence for 5 Hegemony credits.

Battery Bullets
Rank: D
How to Unlock: Kill the Dragun with The Robot.

Frost Bullets
Rank: A
How to Unlock: Unlocked from the start.

Charming Rounds
Rank: B
How to Unlock: Purchased from Doug for 14 Hegemony credits.

Magic Bullets
Rank: B
How to Unlock: Purchased from Doug for 18 Hegemony credits.

Fat Bullets
Rank: A
How to Unlock: Purchased from Ox & Cadence for 6 Hegemony credits.

Angry Bullets
Rank: C
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Blank Bullets
Rank: S
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Orbital Bullets
Rank: A
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Homing Bullets
Rank: B
How to Unlock: Unlocked from the start.

Shadow Bullets
Rank: B
How to Unlock: Unlocked from the start.

Easy Reload Bullets
Rank: C
How to Unlock: Unlocked from the start.

Stout Bullets
Rank: B
How to Unlock: Purchased from Doug for 12 Hegemony credits.

Snowballters
Rank: A
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Remote Bullets
Rank: C
How to Unlock: Unlocked from the start.

Zombie Bullets
Rank: C
How to Unlock: Unlocked from the start.

Flak Bullets
Rank: C
How to Unlock: Purchased from Doug for 28 Hegemony credits.

Silver Bullets
Rank: C
How to Unlock: Purchased from Doug for 8 Hegemony credits.

Gilded Bullets
Rank: B
How to Unlock: Purchase every single gun and item Doug has (its a lot).

Platinum Bullets
Rank: S
How to Unlock: Bought in Ox & Cadence for 200 Hegemony credits.

Chaos Bullets
Rank: A
How to Unlock: Unlock Daisuke and complete his challenge mode or fail it 30 times.

Cursed Bullets
Rank: C
How to Unlock: Defeat the Shadow Magician 5 times.

Chance Bullets
Rank: B
How to Unlock: Unlock Daisuke and reach Chamber 3 in his challenge mode.

Helix Bullets
Rank: B
How to Unlock: Purchased from Doug for 16 Hegemony credits.

Bumbullets
Rank: B
How to Unlock: Purchased from Doug for 26 Hegemony credits.

Bloody 9mm
Rank: B
How to Unlock: Use the Lament Configurium 20 times.

Bionic Leg
Rank: C
How to Unlock: Unlocked from the start.

Shotgun Coffee
Rank: C
How to Unlock: Unlocked from the start.

Shotga Cola
Rank: C
How to Unlock: Unlocked from the start.

Ballistic Boots
Rank: B
How to Unlock: Unlocked from the start.

Magic Sweet
Rank: A
How to Unlock: Unlocked from the start.

Disarming Personality
Rank: C
How to Unlock: Kill The Pilot's Past. You start with this while playing The Pilot.

Mustache
Rank: C
How to Unlock: Unlocked from the start.

Lichy Trigger Finger
Rank: D
How to Unlock: Unlocked from the start.

Lich's Eye Bullets
Rank: S
How to Unlock: Kill The Gunslinger's Past. You start with this while playing The Gunslinger.

Enraging Photo
Rank: D
How to Unlock: Kill The Convict's Past. You start with this while playing The Convict.

Ballot
Rank: C
How to Unlock: Unlocked from the start.

Live Ammo
How to Unlock: Cannot be unlocked. You start with this while playing The Bullet.

Eyepatch
Rank: A
How to Unlock: Purchased from Ox & Cadence for 8 Hegemony credits.

Military Training
Rank: C
How to Unlock: Kill The Marine's Past. You start with this while playing the Marine.

Ring of the Resourceful Rat
Rank: B
How to Unlock: Defeat the Resourceful Rat's first 2 phases.

Cartographer's Ring
Rank: C
How to Unlock: Unlocked from the start.

Amulet of the Pit Lord
Rank: D
How to Unlock: Kill 100 enemies by knocking them into pits.

Ring of Fire Resistance
Rank: C
How to Unlock:

Ring of Miserly Protection
Rank: C
How to Unlock: Unlocked from the start.

Unity
Rank: B
How to Unlock: Unlock every NPC that can appear in The Breach.

Ring of Chest Vampirism
Rank: C
How to Unlock: Unlocked from the start.

Cloranthy Ring
Rank: C
How to Unlock: Unlocked from the start.

Ring of Chest Friendship
Rank: B
How to Unlock: Unlocked from the start.

Ring of Mimic Friendship
Rank: D
How to Unlock: Unlocked from the start.

Ring of Triggers
Rank: A
How to Unlock: Unlocked from the start.

Ring of Ethereal Form
Rank: B
How to Unlock: Unlocked from the start.

Gundromeda Strain
Rank: S
How to Unlock: Purchased from Professor Goopton for 25 Hegemony credits.

Broccoli
Rank: A
How to Unlock: Purchased from Ox & Cadence for 25 Hegemony credits.

Crutch
Rank: B
How to Unlock: Unlocked from the start.

Spice
Rank: A
How to Unlock: Purchased from Ox & Cadence for 7 Hegemony credits.

Liquid Valkyrie
Rank: A
How to Unlock: Unlocked from the start.

Bloody Eye
Rank: B
How to Unlock: Purchased from Ox & Cadence for 7 Hegemony credits.

Gunknight Helmet
Rank: A
How to Unlock: Complete the Grey Mauser's 7th quest.

Gunknight Greaves
Rank: C
How to Unlock: Unlocked from the start.

Gunknight Gauntlet
Rank: C
How to Unlock: Unlocked from the start.

Gunknight Armor
Rank: B
How to Unlock: Unlocked from the start.

Old Knight's Shield
How to Unlock: Open the secret room in the tutorial.

Old Knight's Helm
How to Unlock: Open the secret room in the tutorial.

Old Knight's Flask
Rank: A
How to Unlock: Kill the Dragun 5 times.

Old Crest
How to Unlock: Cannot be unlocked. Found in the Oubliette.

Armor of Thorns
Rank: C
How to Unlock: Unlocked from the start.

Full Metal Jacket
Rank: B
How to Unlock: Unlocked from the start.

Ticket
Rank: A
How to Unlock: Kill the Gattling Gull 20 times.

Heavy Boots
Rank: D
How to Unlock: Unlocked from the start.

Bug Boots
Rank: B
How to Unlock: Purchased from Professor Goopton for 7 Hegemony credits.

Gunboots
Rank: C
How to Unlock: Complete the 2nd chamber elevator shortcut.

Springheel Boots
Rank: D
How to Unlock: Kill 15 Keybullet Kin.

Rat Boots
Rank: C
How to Unlock: Opening Resourceful Rat chests from keys you gain during his 3rd phase.

Coin Crown
Rank: C
How to Unlock: Carry 300 casings at a single time (Golden junk does this instantly).

Oiled Cylinder
Rank: C
How to Unlock: Unlocked from the start.

Ice Cube
Rank: B
How to Unlock: Unlocked from the start.

Rolling Eye
Rank: C
How to Unlock: Unlocked from the start.

Cigarettes
Rank: D
How to Unlock: Unlocked from the start.

Magazine Rack
Rank: C
How to Unlock: Purchased from Trorc for 25 Hegemony credits.

Charm Horn
Rank: B
How to Unlock: Unlocked from the start.

Cog of Battle
Rank: C
How to Unlock: Unlocked from the start.

Metronome
Rank: B
How to Unlock: Unlocked from the start.

Honeycomb
Rank: C
How to Unlock: Unlocked from the start.

Map
Rank: D
How to Unlock: Cannot be unlocked. Can be bought in shops, found in secret rooms, or occasionally given as a reward for clearing rooms or mini-bosses.

Gungeon Blueprint
Rank: S
How to Unlock: Kill the Lich.

Sense of Direction
Rank: D
How to Unlock: Unlocked from the start.

Duct Tape
Rank: A
How to Unlock: Purchased from Ox & Cadence for 10 Hegemony credits.

Gungeon Pepper
Rank: C
How to Unlock: Unlocked from the start.

Antibody
Rank: B
How to Unlock: Unlocked from the start.

Resourceful Sack
Rank: A
How to Unlock: Opening Resourceful Rat chests from keys you gain during his 3rd phase.

White Guon Stone
Rank: B
How to Unlock: Unlocked from the start.

Orange Guon Stone
Rank: A
How to Unlock: Unlocked from the start.

Clear Guon Stone
Rank: D
How to Unlock: Unlocked from the start.

Green Guon Stone
Rank: A
How to Unlock: Unlocked from the start.

Pink Guon Stone
Rank: B
How to Unlock: Unlocked from the start.

Red Guon Stone
Rank: B
How to Unlock: Unlocked from the start.

Blue Guon Stone
Rank: B
How to Unlock: Unlocked from the start.

Glass Guon Stone
How to Unlock: Use a Glass Shrine in order to unlock it as a random drop.

Iron Coin
Rank: C
How to Unlock: Kill the 2nd Chamber boss without getting hit.

Super Hot Watch
Rank: S
How to Unlock: Obtain all 5 master rounds in one life.

Drum Clip
Rank: B
How to Unlock: Unlocked from the start.

Holey Grail
Rank: D
How to Unlock: Obtain the serpent from the Resourceful Rat's lair after beating him (or by other means) and bring it to the Dragun in order to unlock a really difficult 3rd phase known as the Advanced Dragun. Kill the Advanced Dragun to unlock the Holey Grail.

Blood Brooch
Rank: A
How to Unlock: Reach the Abbey of the True Gun from Chamber 2.

Backup Gun
Rank: B
How to Unlock: Unlocked from the start.

Sunglasses
Rank: C
How to Unlock: Purchased from Ox & Cadence for 10 Hegemony credits.

Mimic Tooth Necklace
Rank: A
How to Unlock: Complete the Grey Mauser's 6th quest.

Escape Rope
Rank: D
How to Unlock: Unlocked from the start.

Jetpack
Rank: C
How to Unlock: Unlocked from the start.

Wax Wings
Rank: B
How to Unlock: Unlocked from the start.

Cat Bullet King Throne
Rank: B
How to Unlock: Kill Bullet King 10 times.

Blast Helmet
Rank: D
How to Unlock: Complete the Ledge Goblin's side quest in the breach by knocking their helmet off a whole bunch of times.

Lament Configurum
Rank: B
How to Unlock: Unlock Daisuke.

Monster Blood
Rank: C
How to Unlock: Purchased from Professor Gloopton for 5 Hegemony credits.

Nanomachines
Rank: B
How to Unlock: Purchased from Ox & Cadence for 10 Hegemony credits.

Seven Leaf Clover
Rank: S
How to Unlock: Hit all 4 targets in Winchester's game 3 times after unlocking him.

Number 2
Rank: A
How to Unlock: Enter The Cultist's Past. You start with this while playing The Cultist in co-op mode. Not needed to complete the Ammonomicon.

Gold Ammolet
Rank: B
How to Unlock: Unlocked from the start.

Chaos Ammotlet
Rank: A
How to Unlock: Unlocked from the start.

Lodestone Ammolet
Rank: D
How to Unlock: Unlocked from the start.

Uranium Ammolet
Rank: B
How to Unlock: Unlocked from the start.

Copper Ammolet
Rank: B
How to Unlock: Unlocked from the start.

Frost Ammolet
Rank: B
How to Unlock: Unlocked from the start.

Table Tech Sight
Rank: D
How to Unlock: Unlocked from the start.

Table Tech Money
Rank: D
How to Unlock: Unlocked from the start.

Table Tech Rocket
Rank: C
How to Unlock: Unlocked from the start.

Table Tech Shotgun
Rank: D
How to Unlock: Unlocked from the start.

Table Tech Heat
Rank: D
How to Unlock: Unlocked from the start.

Table Tech Rage
Rank: D
How to Unlock: Unlocked from the start.

Table Tech Blanks
Rank: C
How to Unlock: Unlocked from the start.

Table Tech Stun
Rank: C
How to Unlock: Unlocked from the start.

Heart Holster
Rank: C/B/A
How to Unlock: Unlocked from the start.

Heart Lunchbox
Rank: C/B/A
How to Unlock: Purchased from Ox & Cadence for 5 Hegemony credits.

Heart Locket
Rank: C/B/A
How to Unlock: Purchased from Ox & Cadence for 5 Hegemony credits.

Heart Bottle
Rank: C/B/A
How to Unlock: Purchased from Ox & Cadence for 2 Hegemony credits.

Heart Purse
Rank: C/B/A
How to Unlock: Purchased from Ox & Cadence for 4 Hegemony credits.

Ruby Bracelet
Rank: D
How to Unlock: Unlocked from the start. Can be brought to the Blacksmith to be permanently upgraded to not total garbage.

Sixth Chamber
Rank: A
How to Unlock: Kill a jammed boss. Jammed bosses are found rarely from having a high curse level or using the Hero shrine at the beginning of a run with a character you've killed the past with.

Busted Television
How to Unlock: Cannot be unlocked. Can be picked up after helping make the Chamber 2 elevator. If brought to the Blacksmith, it will be repaired to unlock The Robot.

Coolant Leak
How to Unlock: Cannot be unlocked. You start with this while playing The Robot.

Heart of Ice
Rank: C/B/A
How to Unlock: Unlocked from the start.

Ancient Hero's Bandana
Rank: S
How to Unlock: Complete the 5th Chamber 10 times.

Bloodied Scarf
Rank: B
How to Unlock: Kill the Old King in the Abbey of the True Gun.

Muscle Relaxant
Rank: B
How to Unlock: Unlocked from the start.

Hip Holster
Rank: B
How to Unlock: Unlocked from the start.

Clone
Rank: S
How to Unlock: Kill the Dragun and go back to the Blacksmith. There will be a robot arm near her and she'll tell you to send it up to Chamber 4 with a balloon. On every Chamber, find the arm and send it up all the way to The Breach. Give it to Ox and you will unlock one of the best items in the game.

Sponge
Rank: C
How to Unlock: Purchased from Professor Goopton for 6 Hegemony credits.

Gas Mask
Rank: D
How to Unlock: Unlocked from the start.

Hazmat Suit
Rank: B
How to Unlock: Kill the boss of Chamber 3 without getting hit.

Book of Chest Anatomy
Rank: C
How to Unlock: Shoot a mimic before interacting with it and then kill it.

Gun Soul
Rank: A
How to Unlock: Kill the Dragun.

Shelleton Key
Rank: S
How to Unlock: Steal from the shop 10 times.

Brick of Cash
Rank: B
How to Unlock: Unlocked from the start.

Battle Standard
Rank: D
How to Unlock: Have 2 companions or more at a single time.

Wingman
Rank: A
How to Unlock: Kill The Pilot's past.

Wolf
Rank: B
How to Unlock: Kill The Huntress' past.

Dog
Rank: D
How to Unlock: Kill The Huntress' past. You start with this while playing The Huntress.

Owl
Rank: S
How to Unlock: Unlock the Gunsling King and win 10 of his wagers.

Super Space Turtle
Rank: B
How to Unlock: Reach the end of the Oubliette and defeat Blobulord.

Junk
How to Unlock: Cannot be unlocked. Usually found when destroying chests.

Gold Junk
How to Unlock: Destroy a Red, Black, or Rainbow chest very foolishly.

Lies
How to Unlock: Cannot be unlocked. Can only be found by finding Brother Albern in a secret room and destroying his chest. Not needed to complete the Ammonomicon.

Ser Junkan
Rank: C
How to Unlock: Found occasionally when destroying chests and is upgraded by collecting junk. Can be unlocked by killing a boss while Ser Junkan has at least one upgrade.

R2G2
Rank: S
How to Unlock: Complete the 3rd Chamber elevator shortcut.

Baby Good Shelleton
Rank: S
How to Unlock: Kill the Dragun while having Baby Good Mimic.

Badge
Rank: A
How to Unlock: Kill Blockner.

Chicken Flute
Rank: B
How to Unlock: Kill The Bullet's past.

Space Friend
Rank: B
How to Unlock: Purchased from Ox & Cadence for 25 Hegemony credits.

Pig
Rank: A
How to Unlock: Complete the Grey Mauser's 5th quest.

Turkey
Rank: C
How to Unlock: Use the Companion Shrine twice.

Turtle Problem
Rank: C
How to Unlock: Kill the Dragun while having Super Space Turtle.

Sprun
Rank: A
How to Unlock: Play more than 6 runs (after the release of the final update which is already out).

Baby Good Mimic
Rank: B
How to Unlock: Unlocked from the start.

Blank Companion's Ring
Rank: A
How to Unlock: Unlocked from the start.

Briefcase of Cash
Rank: A
How to Unlock: Kill The Convict's past.

Galactic Medal of Valor
Rank: B
How to Unlock: Kill The Marine's past.

Bullet Idol
Rank: B
How to Unlock: Unlocked from the start.

Riddle of Lead
Rank: S
How to Unlock: Kill the Lich.

Bracket Key
Rank: S
How to Unlock: Complete all elevator shortcuts and finish the Boss Rush.

Elder Blank
Rank: B
How to Unlock: Unlocked from the start.

Teleporter Prototype
Rank: B
How to Unlock: Purchased from Doug for 22 Hegemony credits.

Yellow Chamber
Rank: S
How to Unlock: Kill 10 Confirmed.

Hegemony Credit
How to Unlock: Cannot be unlocked. Found at the end of boss battles and for completing certain quests. Used as a currency for unlocking other items.

Infuriating Notes
How to Unlock: Cannot be unlocked. There are 6 and each can be found in random chests after Beating Chamber 2, having an item be stolen by the Resourceful Rat, entering the Oubliette, obtaining a Master Round, killing the Fuselier, and killing the Dragun. 1 of the notes must be found by killing a mimic. The notes are needed for unlocking the Resourceful Rat's Lair and cannot be found again after being found once.

Many of these enemies can be found in the Resourceful Rat's Lair but I will not be including that. Enemies found in pasts or unqiue enemies created by a boss are not counted in the Ammonomicon. Enemies and bosses in the R&G Department are not counted in the Ammonomicon.

Bullet Kin
Where to Find: Everywhere.

Bandana Bullet Kin
Where to Find: Chambers 1-5. Does not include Bullet Kin wielding AK-47s.

Veteran Bullet Kin
Where to Find: Everywhere (Rare on some floor than others).

Tanker
Where to Find: Chamber 3 and during the Treadnaught boss fight.

Minelets
Where to Find: Chamber 3.

Cardinal
Where to Find: Chambers 1, 4, 6 and the Abbey of the True Gun.

Shroomer
Where to Find: Chambers 3, 5, 6 and the Oubliette.

Ashen Bullet Kin
Where to Find: Chambers 5 & 6.

Mutant Bullet Kin
Where to Find: Chamber 6 and the Oubliette.

Fallen Bullet Kin
Where to Find: Chamber 6.

Chance Kin
Where to Find: Everywhere. Runs by you at the start of a room and then flees to disappear.

Keybullet Kin
Where to Find: Everywhere. Runs by you at the start of a room and then flees to disappear.

Confirmed
Where to Find: Everywhere very rarely.

Red Shotgun Kin
Where to Find: Everywhere.

Blue Shotgun Kin
Where to Find: Everywhere.

Veteran Shotgun Kin
Where to Find: Everywhere (Rarer on some floors than others).

Mutant Shotgun Kin
Where to Find: The Oubliette.

Executioner
Where to Find: Chambers 2-5.

Ashen Shotgun Kin
Where to Find: Chambers 5 & 6.

Shotgrub
Where to Find: Chamber 6.

Sniper Shell
Where to Find: Chambers 2-5 and the Oubliette.

Professional
Where to Find: Chambers 2-5 and the Oubliette, but much more rarely.

Gummy
Where to Find: Chambers 4-6. The minion it spawns is not counted in the Ammonomicon.

Skullet
Where to Find: Chambers 4-6 and the Abbey of the True Gun.

Skullmet
Where to Find: Chambers 4-6.

Spent
Where to Find: Chambers 4-6 and the Abbey of the True Gun in large groups.

Creech
Where to Find: Chamber 6.

Hollowpoint
Where to Find: Everywhere.

Bombshee
Where to Find: Chamber 3.

Rubber Kin
Where to Find: Chambers 1-4.

Tazzie
Where to Find: Chamber 1-4.

King Bullat
Where to Find: Everywhere.

Pinhead
Where to Find: Everywhere but Chamber 6.

Nitra
Where to Find: Everywhere but Chamber 6.

Arrowkin
Where to Find: Shoot a weak enemy with the Devolver and transform it into an Arrowkin.

Blobulin
Where to Find: Kill a Blobuloid and it will split into two Blobulins.

Blobuloid
Where to Find: Kill a Blobulon and it will split into two Blobulons.

Blobulon
Where to Find: Everywhere.

Poisbulin
Where to Find: Kill a Poisbuloid and it will split into one Poisbulins.

Poisbuloid
Where to Find: Kill a Poisbulon and it will split into two Poisbuloids.

Poisbulon
Where to Find: Chambers 3-6.

Blizzbulon
Where to Find: Chambers 4 & 6.

Leadbulon
Where to Find: Changers 5 & 6.

Poopulon
Where to Find: Chamber 6 as well as the Oubliette and the Abbey of the True Gun.

Bloodbulon
Where to Find: Chambers 4-6 as well as the Abbey of the True Gun.

Skusket
Where to Find: Chambers 3 & 4 as well as the Abbey of the True Gun.

Bookllet
Where to Find: Chambers 1, 4, and 6.

Blue Bookllet
Where to Find: Chambers 1, 2, 4, and 6 rarely.

Green Bookllet
Where to Find: Chambers 1 & 2 rarely.

Gigi
Where to Find: Chambers 1 & 3 as well as the Oubliette.

Muzzle Wisp
Where to Find: Chambers 2, 3, 5, and 6.

Muzzle Flare
Where to Find: Chambers 4-6.

Cubulon
Where to Find: Everywhere but Chamber 1.

Chancebulon
Where to Find: Every non-secret Chamber.

Cubulead
Where to Find: Chambers 5 & 6.

Apprentice Gunjurer
Where to Find: Chambers 1, 2, 3, 5, 6 and the Abbey of the True Gun.

Gunjurer
Where to Find: Chambers 4-6 and the Abbey of the True Gun.

High Gunjurer
Where to Find: Chambers 3-6.

Lore Gunjurer
Where to Find: Chambers 4-6.

Gunsinger
Where to Find: Chambers 1, 2, 3, 6 as well as both secret Chambers.

Aged Gunsinger
Where to Find: Chmabers 3-6 and the Abbey of the True Gun.

Ammomancer
Where to Find: Chambers 4-6.

Jammomancer
Where to Find: Chambers 3 & 4.

Jamerlengo
Where to Find: Chambers 3 & 4 rarely.

Wizbang
Where to Find: Chambers 4-6 as well as the Abbey of the True Gun.

Mimic
Where to Find: When looking at a chest, boss item pedestal, or secret room wall; there is a chance that it will subtly move/breathe. Shoot it or interact with it to starting fighting a mimic

Gun Fairy
Where to Find: Low chance to spawn when breaking a pot on any Chamber.

Bullat
Where to Find: Everywhere but Chamber 6 and can spawn after killing a King Bullat.

Shotgat
Where to Find: Everywhere but Chamber 6 and can spawn after killing a King Bullat.

Grenat
Where to Find: Everywhere but Chamber 6 and can spawn after killing a King Bullat.

Spirat
Where to Find: Everywhere but Chamber 6 and can spawn after killing a King Bullat.

Coaler
Where to Find: Chambers 3, 5, and 6.

Gat
Where to Find: Chamber 3 and the Oubliette.

Det
Where to Find: Chamber 3. Either variant works.

Gunzookie
Where to Find: Chambers 3-5.

Gunzockie
Where to Find: Chamber 3-5 rarely in the place of a Gunzookie.

Bullet Shark
Where to Find: Chambers 2 & 3.

Great Bullet Shark
Where to Find: Chambers 5 & 6.

Tombstoner
Where to Find: Rarely in Chamber 6 or during The Lich boss fight.

Gun Cultist
Where to Find: Chambers 3, 5, 6 and the Abbey of the True Gun.

Beadie
Where to Find: Chamber 2, the Oubliette, and during the Beholster boss fight.

Gun Nut
Where to Find: All chambers and the Abbey of the True Gun.

Spectral Gun Nut
Where to Find: Chambers 5 & 6.

Chain Gunner
Where to Find: Chambers 1, 2, 4, and 5. Also appear in The Bullet's past.

Fungun
Where to Find: Chamber 3 and the Oubliette.

Spogre
Where to Find: Chamber 3 and the Oubliette.

Mountain Cube
Where to Find: Chamber 4.

Lead Cube
Where to Find: Chamber 5. Cannot be killed but "dies" after clearing a room.

Flesh Cube
Where to Find: Chamber 6. Cannot be killed but "dies" after clearing a room.

Lead Maiden
Where to Find: Chambers 2, 5, 6 and the Abbey of the True Gun.

Misfire Beast
Where to Find: Chambers 3 & 4. Killing its clone does not count.

Phaser Spider
Where to Find: Chambers 2-5.

Killithid
Where to Find: Chambers 3-5. Killing it's clones does not count.

Gripmaster
Where to Find: Everywhere, but rarely. Cannot be killed but "dies" after clearing a room and not already having attacked.

Tarnisher
Where to Find: Chambers 2, 3, and 5.

Shambling Round
Where to Find: Chambers 3 & 6. Must be fully destroyed to count as killed.

Shelleton
Where to Find: Chambers 3-6.

Agonizer
Where to Find: Chambers 4-6.

Revolvenant
Where to Find: Chambers 5 & 6.

Gun Reaper
Where to Find: Chambers 4-6. Cannot be killed but "dies" after clearing a room.

Lord of the Jammed
Where to Find: Reach 10 curse. Cannot be ever killed and is added to the Ammonomicon upon appearing for the first time.

Fuselier (Mini-boss)
Where to Find: Chambers 2-5. Room is marked ahead of time.

Blockner's Ghost (Mini-boss)
Where to Find: Chambers 2-5 rarely.

Shadow Magician (Mini-boss)
Where to Find: Chamber 2-5 rarely.

Gatling Gull
Where to Find: 1 of the 3 bosses in Chamber 1.

Smiley
Where to Find: Part of the Trigger Twins boss in Chamber 1.

Shades
Where to Find: Part of the Trigger Twins boss in Chamber 1.

Bullet King
Where to Find: 1 of the 3 bosses in Chamber 1.

Blobulord
Where to Find: Put out the fireplace in Chamber 1 with some kind of water or goop and use 2 keys to unlock the entrance to the Oubliette. Blolbulord is the only boss of the Oubliette.

The Beholster
Where to Find: 1 of the 3 bosses in Chamber 2.

The Gorgun
Where to Find: 1 of the 3 bosses in Chamber 2.

Ammocanda
Where to Find: 1 of the 3 bosses in Chamber 2.

Old King
Where to Find: Obtain the Old Crest in the Oubliette and bring it to the altar room in Chamber 2 to unlock the entrance to the Abbey of the True Gun. The Old King is the only boss of the Abbey of the True Gun.

Treadnaught
Where to Find: 1 of the 3 bosses in Chamber 3.

Cannonbalrog
Where to Find: 1 of the 3 bosses in Chamber 3.

Mine Flayer
Where to Find: 1 of the 3 bosses in Chamber 3.

The Wallmonger
Where to Find: 1 of the 3 bosses in Chamber 4.

High Priest
Where to Find: 1 of the 3 bosses in Chamber 4.

Kill Pillars
Where to Find: 1 of the 3 bosses in Chamber 4.

Dragun
Where to Find: The only boss of Chamber 5.

HS Absolution
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as The Pilot.

Black Stache
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as The Convict.

Interdimensional Horror
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as The Marine.

Dr. Wolf's Monster
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as The Huntress.

The Last Human
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as The Robot.

Agunim
Where to Find: Assemble the Bullet That Can Kill The Past and beat the Dragun as the Bullet.

Cannon
Where to Find: Kill Agunim during The Bullet's past and proceed further.

The Lich
Where to Find: Kill HS Absolution, Black Stache, Interdimensional Horror, and Dr. Wolfe's Monster and stand on the revolver platform before obtaining the Gun That Can Kill The Past. A hand will grab you and take you to Chamber 6. The Lich is the only boss of Chamber 6.

Door Lord
Where to Find: Has a very low chance to replace the boss of Chamber 2, 3 or 4.

Blockner
Where to Find: After finding Sir Manuel's remains in the tutorial and speaking to him, he will tell you to go find and kill the traitor. After this, Blockner can be found in Chamber 3.

The Resourceful Rat
Where to Find: After assembling the Bullet That Can Kill The Past, the Gnawed Key will appear in the shop in place of the Prime Primer for 999 casings. This 1000 is a cumulative total that can be added towards over many runs. After buying the key once, it will appear every run after then for 115 casings and cannot be discounted in anyway. In chamber 3. there will be a room with rats in. Walk around the room for a bit to find a trap door buried. To unlock the trap door, walk on it a bunch and then use a key. Inside is a minecart rail and at the end you will need to use 2 blanks in order to reveal a wall and then a 2nd wall further in. Use the Gnawed key at the grate to go to the Resourceful Rat's Lair. Inside here, after dropping down once more, use the cheese arrows at the end of each Infuriating Note (located in the Ammonomicon) to find your way around. FINALLY, at the end you will be able to fight the Resourceful Rat as the only boss of this secret chamber.

Whew! My hand hurts now. Anyway, that is the complete catalog of every gun, item, enemy, and boss in Enter the Gungeon. Let me know if I missed anything or if anything is incorrect. Also, let me know if you want this guide expanded to including synergies or something. I know this guide is purely Ammonomicon stuff, but I don't mind making additions. I hope you enjoyed this guide and find it useful on the path towards being a true Gungeoneer.

Update Log:

4/7/2021 - Changed title and added update log.

7/2/2020 - Guide is complete and released!