Alien Life Forms (LWR)

Support Units

Like XCOM's own support units, these aliens are not especially threatening in a simple firefight, but instead improve the effectiveness of other alien units. They can heal and buff the stronger aliens in the collective, forcing the player to be more thoughtful in their target selection and damage output.

Sectoid

Appears	Level 1
Ammo: {{{ammo}}}

Sectoids have low mobility, HP, and aim. They have access to Mind Fray, Psi Panic, and Mind Merge. All Sectoids have the Gunslinger perk so they have no aim penalty when shooting with their plasma pistols at a distance.

Their signature Mind Merge ability is significantly more powerful, now granting the target +25 to aim, crit, and will, but has a long cooldown. Sectoid squad leaders get the Low Profile and Psi Mastery perks making them significantly more dangerous.

Drone

Appears	Level 1
Ammo: {{{ammo}}}

Drones can be encountered right from the beginning of the game. They can come in groups of their own or attached to Sectoid squads, and later they will accompany more powerful mechanized units like Cyberdiscs and Sectopods. Their holo rounds so are effective at making your units easier to hit. Drones, like all mechanized units, have some damage reduction and are hardened. Their constant light cover from flying with damage reduction and ability to mutually repair can make them difficult to kill.

Thin Man

Appears	Level 1
Ammo: {{{ammo}}}

Thin Men have high mobility, mediocre aim, and low will. The can also jump to any height making them extremely dangerous when fighting at varying elevations. They can spit acid clouds at your units, leading to a corrosion effect that lowers aim and mobility by 20%, removes flat DR, and prevents passive healing for the remainder of the battle.

Outsider

Appears	Level 1
Ammo: {{{ammo}}}

Outsiders are quite dangerous. They have passive HP regeneration, high aim, and decent HP. You'll first encounter them shepherding their UFOs, waiting inside for you to approach (unless you play on Brutal or Impossible difficulties where they will also be present on the first mission). Their DR, HP pool, and regeneration means that it will take a concerted effort from the whole squad to take them down early game. Be careful though, they all have the close combat specialist ability, meaning moving too close to them can be extremely dangerous.

Their Growth ability causes them to gain increased stats as the mission goes on, beginning from the start of mission. Leaving them alone until the end of the mission is ill-advised as they can become too strong to fight. On larger UFOs, Outsiders will be much more common, sometimes appearing in large groups. They will occasionally patrol and are not always found in the command room.

When you first meet them, fighting Outsiders in a war of attrition across cover is a bad idea, since their HP regen, relatively high damage, and accuracy with their Alien Carbines means they may well win. Neutralizing the Outsider with Flashbangs and Suppression while you move your troops up to set up for a one turn kill is more effective. Note that their regenerative abilities will increase over the course of your game.

Chryssalid

Appears	Level 1
Ammo: {{{ammo}}}

Chryssalids have great mobility and defense, and gain the Hardened ability, making them extremely agile armored threats. They also deal significant damage and will corrode any unit they hit, meaning you should attempt to kill them before they can get too close.

Explosives remain an effective counter to Chryssalids, since they'll frequently charge in a tightly packed group on first sight, and are difficult to hit with most weapons. Similarly, Concussion Grenades can debilitate a whole group of Chryssalids by reducing their mobility -- this means they won't be able to move and attack any units on the next turn if there are no units close to them. Chryssalids are immune to acid, so Acid Grenades won't reduce their mobility. A Close Combat Assault can frequently finish off weakened Chryssalids. The MEC Flamethrower is also quite effective; aside from the damage (especially with the Jellied Elerium upgrade) it can cause the Chryssalids to panic, and they may then run away from your soldiers instead of towards them.

Damaging them can drastically reduce their lethality thanks to Red Fog lowering their mobility and melee damage.

Zombie

Appears	Level 1
Ammo: {{{ammo}}}

Zombies are fast units with high health pool. However, they are not hardened and do not take cover so you can usually crit them for high amounts of damage. They can occasionally spawn as a member of Chryssalid pods on any mission, and it is also be possible to encounter them as a special pod spawn during Terror missions.

Damaging them can drastically reduce their lethality thanks to Red Fog lowering their mobility and melee damage.

Seeker

Appears	Level 2
Ammo: {{{ammo}}}

Seekers can be found both in pods made up entirely of Seekers, and accompanying squads of other aliens. This makes them dangerous, since a Seeker itself isn't much threat, but a Seeker supporting other aliens can be a deadly distraction. As mechanized units they have some damage reduction and are hardened. However, if they happen to get close to your units they may strangle them, incapacitating them and gaining +2 DR when strangling. Each turn the incapacitated units that are being strangled will take more and more damage. It is advised to try to kill them before they strangle as it can be difficult to remove them when strangling due to their increased resiliency.

Battle Scanners and the Proximity Sensor item can detect and uncloak nearby Seekers, providing an early counters to Seekers. They have a habit of going into Overwatch while in stealth, so if you're waiting out Seekers without a Battle Scanner, try moving a soldier, one might reveal itself to take a pot shot at you. Any explosive/area effect attacks (bar the MEC Flamethrower; Seekers are fireproof - though an 'IMMUNE' popup will still appear) that catch an invisible Seeker in their area will force them to decloak.

Floater

Appears	Level 2
Ammo: {{{ammo}}}

Floaters tend to fly (granting +30 defense) and gain the Tactical Mobility ability, granting them +15 defense while in flight or in cover. This makes them quite elusive. They also get +20 bonus aim when at an elevation meaning their aim can be quite high. In combination they can be quite deadly as accurate and difficult to hit enemies. Steadying your weapons can make it easier to hit them when they are flying high at a distance.

Muton

Appears	Level 2
Ammo: {{{ammo}}}

Mutons are sturdy aliens that gain a lot of DR when protected by cover. They start with Alien Carbines and later upgrade to Alien Rifles.

Muton leaders have a Deflection Shield ability which activates when they end their turn on a move or with AP remaining, granting them defense and crit resistance against ranged attacks that scales with distance. They have access to the Blood Call ability which will grant various stat increases to allies in range, including double mobility. This can catch an unwary player off guard as a Muton moves many tiles to flank one of their soldiers.

Overall, Mutons create resilient roadblocks in the enemy formations that are best dealt with by flanking or removing their cover.

Unlike some of the other aliens, Muton intelligence is low when can lead to poor strategies like: running out into the open, performing poor attacks, or even retreating early if some of their squad mates have been killed.

Cyberdisc

Appears	Level 3
Ammo: {{{ammo}}}

Cyberdiscs are usually accompanied by two to three Drones, and usually prefer to throw their grenade if an eligible soldier is in range rather than shooting.

Cyberdiscs pose a significant threat throughout the game due to high aim and high damage. They can transform between open and closed states: their open state is required to act and their closed state will grant them hardened and +6 DR. If they take damage in their open state, they will automatically close. Thus, they are best dealt with through high damage single attacks (e.g. a Mayhem sniper).

Their movement range can take you off guard as it's close to that of a Chryssalid; if they're not dealt with quickly or retreated from, they are very likely to flank and hit you with raw firepower or simply fire long-range explosives at you.

The Drones escorting a Cyberdisc are of course more dangerous as well (see the main Drone entry), for two reasons. First, they can tag a target with Holo Rounds, making it easier for the parent Cyberdisc (and any other enemies, for that matter) to hit the victim. Second, they can fix any damage you have done to the Cyberdisc with their Repair ability.

Mechtoid

Appears	Level 4
Ammo: {{{ammo}}}

Mechtoids will appear with Sectoid escorts, and later with Sectoid Commanders. They are very resilient units that deal high damage and have moderate aim.

Mechtoids are one of the few "big" units vulnerable to psionics - Mind Fray will restrict their movement and prevent them from charging to flank as well as reducing their accuracy. Psi Panic will completely disable a Mechtoid. Their will is a little higher than regular troops, but not stellar, so they are excellent targets for psionic abilities. Chem Grenades are also useful as Mechtoids have a significant amount of flat DR and the corrosion will lower their accuracy.

The Psi Shield granted to Mechtoids by Mind Merge grants a massive amount of temporary health. As a result, it is ideal that you find and kill the Sectoid that set up the link (helpfully indicated by the purple streams) before targeting the Mechtoid.

While Mechtoids do not explode for damage, a Mechtoid that falls backwards in a fight it will crush cover it lands on. Be careful not to destroy your own cover in close quarters combat.

Berserker

Appears	Level 4
Ammo: {{{ammo}}}

Berserkers can also be Squad Leaders, meaning the first Berserkers you see could have terrifying amounts of health.

Like Chryssalids and Zombies, anything you can do to slow down a Berserker will greatly reduce its threat. They are Hardened and as such, will have a reasonable amount of DR. They are particularly weak to psionics due to their low will. Concussing a Berserker will reduce its movement range to well below Concussion throw range, so is a good way to neutralize a Berserker you're not ready to kill.

Berserker Leaders have the Overpower ability, which grants them an overpowering aura. Non-SHIV XCOM units within their line of sight perform a will test against 50% of the their will after each move or action taken. Failing this will test ends the unit's turn immediately. This means low will multi-action units are much less effective when there is a Berserker leader present. This can countered with psionics, either by reducing their will or causing them to panic. Additionally, the Steadfast ability (can be gained by equipping an alien trophy) grants immunity to being overpowered.

Sectoid Commander

Appears	Level 5
Ammo: {{{ammo}}}

Sectoid Commanders represent a substantial step up from their early game counterparts, and a substantial step up in terms of difficulty. An unprepared player could easily have their entire squad decimated by a Sectoid Commander.

They carry new psionic abilities as well as much better statistics. Sectoid Commanders are brave, and greatly prefer using psionic abilities over shooting, making them even more effective in their role. They all have the Psi Mastery ability, and will be able to use multiple psionic abilities each turn.

Their Greater Mind Merge is now extremely powerful, granting the target +100 aim and crit in addition to the +25 will and healing. They can also use Mind Control which will turn one of your soldiers against you.

They also gain the Distortion ability which distorts reality around them, making non-psionic attacks deal 65% less damage against them, and granting nearby allies +10 defense. In addition, Distortion will prevent squadsight shots from being able to target them.

Everything considered, these will likely be the most difficult aliens you fight when they are first revealed.

Heavy Floater

Appears	Level 6
Ammo: {{{ammo}}}

The Heavy Floater is a significant improvement over the original Floater. Unlike regular Floaters, Heavy Floaters can throw grenades, and with the Bombard perk, they can throw them very far.

They also have Rapid Reaction granting them the ability to trigger overwatch against units they can't originally see, and do so 3x per turn.

They also have Critical System Targeting and hit quite hard (often with high aim due to elevation), so tanking their shots with mechanical units is quite costly.

Muton Elite

Appears	Level 6
Ammo: {{{ammo}}}

Muton Elites are looking similar to Mutons, but with a red armor and a helmet.

They have a lot of firepower at their disposal. Their heavy plasma weapons are both destructive and highly damaging, and they still benefit from Blood Call. They all have the Shredder ability which means your hardened units should take care to avoid their shots.

They are even sturdier then their regular and beserker counterparts as they have more defensive perks and more innate DR.

Sectopod

Appears	Level 7
Ammo: {{{ammo}}}

Sectopods are massive mechanical war machines. They represent one of the two late game enemies that are extremely dangerous. Taking them down without suffering casualties may not be possible. As with all aliens, their strength and power progresses with time, making them even more dangerous as the war drags on.

They have extremely high damage and extremely high aim. Tanking their shots should only be done by very resilient units, and they will still likely lose the majority of their health.

Not only do they output incredible offensive power, their HP and flat DR is extremely high. It is almost mandatory to bring some form of corrosion when fighting them in order to do reasonable amounts of damage.

By the time you encounter these units, you should hopefully be well on your way to finishing your campaign!

Ethereal

Appears	Level 8
Ammo: {{{ammo}}}

The floating psionic leaders of the alien race the most dangerous enemies a Commander will encounter. Using a Psionic Lance attack that is based on will as well as the feared Mind Control and Rift abilities, Ethereals represent the pinnacle of psionic deadliness. Moreover, with Psi Mastery they can perform 2 attacks each turn.

Just like Sectoid Commanders they have the Distortion ability, granting immunity to squadsight and reducing any damage dealt to them by 65%. They also regenerate health, have innate defense, and the Overpower ability. Overall, this makes them extremely resilient.

They represent the other late game enemy that is extremely dangerous and likely to cause fatalities and/or full squad defeats. Fighting an ethereal often results in a pyrrhic victory, if a victory at all. Take great care when engaging one.