This is a quick guide to all the enemies you may encounter in "The Bureau" in your attempt to defeat the threat to Earth.

Units that are alive (i.e. is a biological being, not mechanical) are listed here.

NOTE: Sectopod is considered a mechanical unit even though there is a special sectoid inside.


Sectoid

Sometimes call "the Greys", they are the smaller humanoid aliens with huge eyes and round head that we often associate with "alien abductions". They are the weakest enemies you'll face, usually armed with only plasma pistols, and has no armor or shields.

There is only one type of Sectoid. But they usually come in large numbers and can be messy if they flank you in mass. Sectoids disappear by endgame.

Nothing special involved to killing them. They are pretty easy to kill.


Silacoid

Sort of "blob" of black slime, it will attack units and prevent them from moving or attacking while draining health. Fortunately, they are relatively easy to kill, esp. with energy weapons. However, they are fast and acrobatic, easily jumping up walls and such.


Outsiders / Zudjari

The Outsiders, which is the name bestowed on by XCOM, actually called themselves the Zudjari, according to the "Infiltrator". They comprised the vast majority of the invasion force.

The Outsiders come in large variety of units, as they will be listed below:


Outsider (grunt)
Outsider Elite

The lowest rank of the Outsiders, the grunts (identified as "Outsider" in the game) may be leading some Sectoids around, or be grunts for higher-ranked Outsiders. Generally armed with "Laser SMG" and grenades, they do not wear any sort of armor or shields, but they will hide in cover effectively, and use grenades to flush you out of cover. If you don't shoot at them, they may rush you and melee you.

Grunts disappear by four major operation, to be replace mostly by Outsider Elite, who do have armor and shields, and thus, much harder to kill.

Best killed via flanking, lifting, or even grenades, but generally, just wait for them to pop-up, and shoot their head off.


Sniper -- Rocket
Sniper Elite

Sniper - Rocket is armed with the Blaster Launcher. I personally don't recall seeing this though, it's listed elsewhere, so I'm including it.

Sniper Elite is armed with Plasma Sniper Rifle. Being "elite", the sniper will be wearing armor and shield.

They tend to stay far back, in cover, and shoot at any one exposed. Either lift them, or counter-snipe them (with your scout-sniper, or do it yourself). You generally get a warning laser that you're being tracked.

Phantom
Phantom Elite

Phantom is an Outsider that gained the ability to cloak, but they are still visible albeit quite faint, even when cloaked. They can be very deadly if they manage to flank you.

Elite version has shields and armor. Generally armed with Laser SMGs, and Pulse Lasers later, and plasma cannon later.

Phantoms will rush or flank. They generally have weaker shields than other Outsider units.

Scout

Scout is an late-game outsider unit that has a short-range teleporter and can teleport between cover. It will rush if presented a chance. It is generally armed with plasma cannon or pulse laser.

Lift them or pin them down with turret then flank them.


Shield Commander
Tech Commander
Minion Commander
Psion Commander

The commanders are powerful units that can either summon reinforcements, or have powerful capabilities to make lives difficult for you. They are also heavily armored and shielded, and are armed with heavy weapons and grenades. They generally stay way back and let their minions do the work.

Shield commanders endow shields onto live units (not drones or sectopods)

Tech commanders can summon drones (or advanced drones) as well as raise walls from the field and summon turrets.

Minion Commanders can summon Silacoids, or Sectoids.

Psion Commanders have full psi-power and can lift or psi-control your units. It can also "clone" itself (but it's mostly an illusion / decoy, similar to agent's "distraction/decoy" ability.


Muton
Elite Muton
Muton is basically a mini-tank, and NOT a part of the Zudjari. It is suspected that the Mutons that came with the Zudjari are mercenaries. It is EXTREMELY heavily armored, and thus VERY VERY hard to kill. Its armor is segmented with separate coverage for chest, the 4 limbs, and head.

Elite Muton have shields on top of that. Furthermore, they have jetpacks that let them jump to you and deliver melee smash that will bring major hurt to you or your agents.

They are generally armed with scatter laser (aka Laser shotgun), though elites can also throw plasma field grenades that is similar to your agent "plasma field" ability.

Mutons can be lifted, but they will just barely leave the ground instead of 30 ft in the air. You can also stick grenades to them, or use "bust armor" ability on them.



Drone
Advanced Drone

Drone flies up in air and shoots down at your units. It can count as "flanking" and do extra damage. Don't get flanked.

Advance drones are more heavily armored, as well as having a secondary capability such as a heal beam or a lift beam. They are your primary targets. And a tech commander can summon a lot of them. Thus, hit tech commanders. first.


Sectopod
Heavy Sectopod

Sectopods are mininiature walker tanks, and are indeed sometimes called "walkers" by your fellow agents. It is armed with a laser gatling. and is even MORE heavily armored than Mutons. However, its armor are similarily segmented like a Muton's.

One weak spot of the sectopod is the implanted sectoid inside the cockpit, but the cockpit "windshield" is very hard to penetrate. if you do manage to do so, you can kill it from within.

Sectopod is also vulnerable to hits from the rear, and thus, flanking is very important.

Heavy Sectopod has even more armor and is armed with blaster launcher, not laser gatling. Stay behind cover.

Sectopods are too heavy to be lifted high up. But they can be temporarily disabled through lift commander.


Titan

The most dangerous single enemy you'll see, Titan is basically a SUPER-drone, that has a heavy beam that can kill you in a single shot. In fact, it will demolish any cover you hide behind. But it takes a while to recharge for a second shot, giving you a chance to shoot back.