you need to type sv_cheats 1 in your console for these to work
tf_bot_add - add a bot!
tf_bot_melee_only 1 - bots only use melee
tf_forced_holiday Enables holiday mode (0: default; 1: Birthday; 2: Halloween; 3: Christmas; 4 = Valentine's Day; 5 = Meet the Pyro (Unused); 6 = Full Moon)
tf_powerup_mode 1 - mannpower mode
tf_grapplinghook_enable 1 - allow grappling hook
ent_create eyeball_boss teamnum 5 - creates monoculus
ent_create merasmus - creates merasmus
ent_create headless_hatman - creates this guy
ent_create tank_boss - spawns a tank
Buildings
ent_create obj_sentrygun - Spawns in a level 1 Sentry Gun where the player is aiming
ent_create obj_dispenser - Spawns in a level 1 Dispenser where the player is aiming
ent_create obj_teleporter - Spawns in a level 1 Teleporter where the player is aiming
Optional parameters (work with certain commands):
teamnum <2/3>: Team RED/BLU (values other than 2 or 3 will spawn a BLU building that will be attacked by both teams, but if it is a Sentry it will only attack BLU)
defaultupgrade <0/1/2>: Level 1/2/3 building
spawnflags <number>: Examples include spawnflags 2 for invulnerability, 4 to make the building upgradable, and 8 to give Sentry Guns infinite ammo
Example: ent_create obj_sentrygun teamnum 2 defaultupgrade 2 spawnflags 8 spawns a level 3 RED Sentry Gun with infinite ammo
Pickups
ent_create item_teamflag - intel that can be capped by both teams
ammo
ent_create item_ammopack_small
ent_create item_ammopack_medium
ent_create item_ammopack_full
heatlh
ent_create item_healthkit_small
ent_create item_healthkit_medium
ent_create item_healthkit_full
mvm credits
ent_create item_currencypack_small
ent_create item_currencypack_medium
ent_create item_currencypack_large
funny stuff
ent_create prop_dynamic solid 6 model models/player/Engineer.mdl defaultanim taunt01 - summons a dancing engineer that block your way (and bomb carts)
ADDCOND
addcond 92 - regenerates hp, ammo
addcond 74 - makes player giant
addcond 75 - makes player gnome
addcond 64 - invisibility
addcond 55 - aoe teammates heal
addcond 56 - crits
addcond 82 - bumper car
OTHER STUFF
mp_disable_respawn_times 1 - instant respawn
mp_teams_unbalance_limit 0 - allow players to pick teams even if it is unbalanced
mp_scrambleteams - scrambles teams
mp_restartgame 1 - restarts the game in 1 second
mp_friendlyfire 1 - turns off/on friendly fire
https://wiki.teamfortress.com/wiki/List_of_useful_console_commands for more
mvm related
currency_give [amount] - gives money
tf_mvm_min_players_to_start [number of players] - sets minimal amount of players to start