X-COM
An organisation funded by multiple nations, X-COM stands for Extraterrestrial Combat Unit.- A-Team Firing: Rookies in particular are prone to firing off shots that hit anything but their intended target. Even with a highly trained and experienced Commander, there are no guarantees of landing a hit.
- Destructive Savior: Potentially during terror missions. X-COM can swoop in and save the day, but stray shots can leave buildings with holes, dead civilians, and destroyed fuel pumps, leaving the surrounding area in ruins.
- Multinational Team: While not as overt as with the rebooted games, the sheer variety of names that soldiers are randomly generated with, ranging from various different cultures, implies that X-COM draws its recruits from around the world.
- Redshirt Army: X-COM has a notorious high fatality rate, since the game's mechanics allow for them to be taken out in a single shot if unlucky.
Aliens
The main enemy faction, out for control of the Earth and the extermination of the human race.- Aliens Are Bastards: They started an unprovoked war against humanity seemingly for just existing, abduct, experiment on and even eat human civilians, destroy cities, attack animals ... and they do all this seemingly For the Evulz.
- The Aesthetics of Technology: Their technology is sleek, shiny and spotless.
- Alien Abduction: Some of them, namely the Floaters and Sectoids, practice this. They even have a specialised UFO called the "Abductor".
- Aliens Steal Cattle: They do this on occasion. It's NOT Played for Laughs like you would expect, though.
- Decapitated Army: The death of their leader, the Alien Brain, causes the entire command structure of the alien forces to dissolve and immediately ends the invasion.
- Fantastic Drug: Sort of. Some UFOs have weird rooms with walls that look like they're covered by shifting blue or orange clouds and have strange silver orbs with red cores. These rooms are revealed to be a form of alien entertainment that stimulate certain sensory regions of the brain. They are described as being similar to hallucinogenic drugs.
- Flying Saucer: Their main method of transportation.
- Insufficiently Advanced Alien: They may be much more advanced than humanity in terms of technology, but their advanced ships are very easy for human technology to bring down, their tech can be easily reverse engineered by a bunch of idiots in an underground burrow, and they don't seem to have any knowledge of shielding tech and can be easily blasted away by human firepower.
- Kill All Humans: Their main mission.
Sectoids
Typically the very first type of alien seen by the player, little humanoid creatures modelled after the standard Grey. They're good shots and some have Psychic Powers, but they're quite easy to bring down with one or two direct hits from a pistol or rifle.
- Alien Blood: They bleed green.
- Black Eyes of Evil: Part of their The Greys image.
- Clone Army: The Sectoids are theorised to be all clones of the same DNA, meaning that you're fighting copies of the same Sectoid over and over.
- The Goomba: Usually the first type of alien encountered (unless you come across Floaters first), have low health and stamina but decent accuracy, and are only really dangerous in groups ... unless they have Psychic Powers. Then they become a NIGHTMARE.
- The Greys: They tick all the boxes - small, grey, slim, large round black eyes, and tend to abduct and mutilate cattle.
- Mascot Mook: One of the first and easiest aliens you encounter, but a Sectoid's face is visible on the cover of the game and they have since become the series mascot.
- Mind Rape: Sectoid Leaders and Commanders can perform this, causing soldiers to panic, go berserk, or fall under alien control.
- Psychic Powers: High-ranking Sectoids are capable of this, causing troops to panic and even fall under Mind Control. Just one Sectoid Leader will completely throw your squad off balance if there are any weak links in your team's psychic resistance chain, although capturing one alive may be worth it, as it lets you develop some Psychic Powers of your own.
Cyberdiscs
The assigned Terror Unit of the Sectoids. Essentially a miniature Flying Saucer that serves as their version of your tanks, with a plasma cannon weapon and an explosive self-destruct when "killed".
- Achilles' Heel: Stun weapons - rather than being shut down and taken alive, they'll automatically explode if shot by a stun bomb.
- Action Bomb: When defeated, they explode with enough force to kill anything in the blast radius.
- Flying Saucer: A Mini Mook version of this.
- Lightning Bruiser: Cyberdiscs are heavily armed, fairly durable and can fly quite far.
- Mechanical Monster: It and the Sectopod are the only true robotic enemies in the game.
- Sinister Geometry: It's basically a reflective chrome disc. That flies. And shoots plasma.
Floaters
Only just above Sectoids in terms of threat level, Floaters are pink humanoids with red capes who have a mechanical sphere in place of legs. It lets them fly.
- Alien Blood: PURPLE blood.
- Beware the Silly Ones: They make look quite silly, with their pink bodies and capes, but they're still capable of dropping any of your men with a single lucky shot.
- Body Horror: Their cybernetic enhancements are visible in the form of a giant gaping hole in their chests, not to mention their anti-grav ball-feet, which are very clearly unnatural.
- Cyborg: The Alien Autopsy performed on a Floater's body shows that the sphere on their bodies is in fact connected to a life support system that takes over the functions of the heart, lungs and digestive system. Capturing a live one will let you see that this system is visible from the outside of their bodies.
- Flight: Via anti-gravity circuits in their Cyborg bodies.
- The Goomba: They have a little more health than the Sectoids, but are still quite easy to take out. Their weapons aren't even as powerful as a Sectoid's - they're just able to do more damage in groups by flying around and having snipers pick off your soldiers.
Reapers
The assigned Terror Unit of the Floaters. They basically look like large, furry, weird-looking animal-like creatures with powerful jaws.
- Achilles' Heel: Explosive weapons - their furry hides are very flammable, after all.
- Alien Blood: Like Sectoids, they bleed green.
- Cartoon Creature: Albeit a very ugly and evil-looking one.
- Fake Ultimate Mook: They're large and intimidating, but they can only attack in melee and can't fit through most of the doors on the level. They have a lot of health and can tank half a clip of rifle shots, but their size makes them a relatively easy target for your troops. They're also very vulnerable to explosive damage.
X-COM being X-COM though, Reapers are still relatively dangerous for an example of this trope, particularly in the early game - its melee attack is a pretty much guaranteed One-Hit Kill before you research actual armour, and unlike the alien ranged weapons, there isn't a possibility of it missing.
- Giant Mook: A Reaper is roughly the size of a Tank, and is just as dangerous.
- Non-Malicious Monster: Unlike the Crysallid or the robotic enemies, it's just a animal acting on its predatory instincts.
- Spare Body Parts: The Alien Autopsy done on a Reaper corpse shows them to have two brains and two hearts.
Snakemen
A more advanced foot soldier, resembling a semi-humanoid snake with a large tail-like foot in place of legs. More dangerous than the Sectoid or Floater, but still manageable, unlike their pets...
- Alien Blood: Yet another alien with green blood.
- Bizarre Alien Biology: They appear to have a naga-like tail, but in actuality it's a "foot". That also contains all their vital organs.
- Dumb Muscle: As noted when "interrogating" one, they're animalistic and predatory, obviously operating under orders from a higher intelligence.
- Slasher Smile: Constantly. Then again, they don't have lips.
- Truly Single Parent: Snakemen reproduce asexually, with each one carrying fifty or so little green eggs in their body at all times. Despite your scientists warning that they could use this to populate the Earth, they never actually lay these eggs in battle, probably because they're too busy blasting your soldiers.
Chryssalids
THE worst type of alien to be up against. Looking something like a silver humanoid lobster, these clawed horrors are the assigned terror unit of the Snakemen and can One-Hit Kill a civilian or unarmoured soldier, turning them into a zombie which upon death bursts open into a new Chryssalid. They're also fast, and can sneak up from the shadows with ease. Have fun!
- Achilles' Heel: Flying units - they cannot hit them if they're two levels above them. Once you manage to procure some Flying Armour, you can just hover two levels above them and use them for target practise.
- Alien Blood: Green. Again.
- Body Horror: They induce this upon anyone they can get their claws on.
- Chest Burster: Any Zombie that's shot dead will burst open into a new Chryssalid. With full time units. And a clear view of you.
- Dark Is Evil: They have dark grey skin, hide in the shadows, and are arguably the most dangerous enemy in the game.
- Humanoid Abomination
- It Can Think: Unlike the Reaper, Chryssalids are clearly intelligent and taking sadistic joy in hunting down and zombifying your soldiers.
- Power Pincers: Used to hold their victims for zombification or slash through armour.
- Shout-Out: The Chryssalids are based around the mutant that appears on the old Penguin cover art for John Wyndham's similarly named novel (though not in the novel itself).
- Slasher Smile: Perpetually, and understandable why.
- Weaksauce Weakness: They're a complete terror, especially in the earliest parts of the game, with 120+ action points and the ability to shred your soldiers in one or two attacks and use the corpses to spawn more Chryssalids... and then you get Flying Armor. Suddenly, these dreaded creatures and their claws are reduced to targets, as your troops can hover outside their range and pelt them with plasma.
- Xenomorph Xerox: Downplayed, but they still have something of a Xenomorph-like appearance, with shiny metallic skin, sharp claws, and animalistic sadism.
- Zombie Apocalypse: If they're not taken out fast enough, they'll start one of these.
Muton
The most powerful of the alien races, resembling purple-skinned human-like beings with light green bodysuits. They're immensely strong and tough, but not very bright, and will tend to forget about your soldiers after a few turns.
- Alien Blood: They bleed orange.
- Cyborg: Like many of the other races, they have cybernetic implants
- Dumb Muscle: They may be dumb, but boy are they tough.
- Heavily Armored Mook: They can typically survive two Heavy Plasma shots at point-blank range.
- Heroic Build: Inverted - they have traditional extremely muscular G.I. Joe-size bodies common of a action hero, but they are villainous.
- Human Aliens: They look very human - the main differences are their purple skin, lack of noses, and huge builds.
- Informed Attribute: The examination of a live specimen claims that they are intelligent, but then contradicts itself by talking about how they need telepathic commands to survive.
- Master of All: With the exception of Psychic Powers, which they lack, they're strong, tough, fast, use powerful weapons, can kill any soldier in one melee hit, and have some resistance to psionic attacks.
- Purple Is Powerful: They have purple skin.
- Wallpaper Camouflage: Their green suits allow them to blend in with vegetation, especially in jungle environments
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Celatid
The assigned terror unit of the Mutons, a bizarre creature that looks somewhat like a giant flying kidney that can spit a acidic substance that is the most powerful non-explosive weapon in the game.
- Alien Blood: They bleed blue.
- Beast of Battle: The Alien Autopsy done on the Celatid shows that it doesn't even have a brain.
- Explosive Breeder: The scientific analysis determines that they can clone themselves at a rapid rate. This doesn't appear in-game, mainly because of how overpowered it would be.
- Flight: Like the Floaters.
- Psychic Powers: They appear to have some kind of ability to detect human brainwaves, which allows them to hone in on their targets.
- Starfish Aliens: Basically giant flying kidneys hovering above some kind of grotesque pod (at least in the image shown when analysing a live specimen) that can spit corrosive venom and detect human brainwaves.
Silacoid
These weird purple rock-like creatures are essentially like pets to the Mutons. While they're the least dangerous alien lifeform, they can generate enough heat to melt rocks, and can use this on your soldiers.
- Blob Monster: Purple blobs with brown rock formations along their bodies.
- Goldfish Poop Gang: Easy to outrun, only have a melee attack, and basically serve as target practise. Unless they get in close enough.
- Mighty Glacier: They're very tough and immune to fire, but can't move very fast.
- Non-Malicious Monster: They are primitive creatures forced to work for the aliens via control implants.
- Silicon-Based Life: As their name implies.
- Shout-Out: Their appearance and physiology appear to be inspired by the Horta from Star Trek.
Ethereals
The apparent masterminds of the invasion, resembling mysterious, faceless cloaked mages with vast Psychic Powers and plasma Hand Cannons. They only appear later in the game, and often only for the most important missions, such as building bases or retaliating against X-COM.
- Alien Blood: They bleed silver, although it appears as red during the Alien Autopsy screen.
- Black Cloak: Well, saffron cloak. But just as intimidating.
- Body Horror: Without their cloaks◊, we get to see that their bodies are essentially just withering away - they're described as being "physically retarded", their muscles are severely atrophied and seem unusable, their organs, including their eyes, don't seem to function at all, and your scientists are at a loss as to how they're even alive at all.
- Co-Dragons: The entire Ethereal race serve as this to the Alien Brain.
- Mind Rape: Their speciality, although they also carry around a handgun.
- Psychic Powers: FAR more so than the Sectoids, being able to easily cause anyone who doesn't have sufficient protection to panic or fall under their control.
- Power Floats: Unlike the Floaters or Celatids, they seem to be capable of flying under their own power.
- Squishy Wizard: Their bodies have atrophied so much that their self-sustaining functions have to be governed by their immense Psychic Powers. Which does not prevent them from having the best armour values and second best hit point totals among the non-terror unit aliens. Their huge cloaks present a considerably larger profile than their actual bodies... hitting the cloak is not necessarily hitting the Ethereal. Plus, there isn't much to damage in their actual bodies. However, their brains still need an ample supply of blood, and if they lose too much blood because of serious injuries, they die.
Sectopods
The assigned terror unit of the Ethereals, a gigantic chicken-legged Mini-Mecha that is a absolute terror to deal with. They possess laser weaponry and can be remote-controlled by a Ethereal.
- Achilles' Heel: They may be resistant to plasma weaponry, but they actually take nearly double damage from the weaker laser weaponry. If you're prediciting that you may be encountering one on a mission, it might be a good idea to dust off your old Heavy Lasers unless you've got some Blaster Launchers.
- Boss in Mook Clothing: A tank-sized robot that is virtually immune to conventional fire, resistant to plasma, and has a extremely dangerous laser weapon. And they're the Ethereal's terror units.
- Chicken Walker: Don't make fun of it if you value your life.
- Evil Counterpart: To your Tanks.
- Giant Mook: About the size of your Tanks, and possibly even more dangerous.
- Motion-Capture Mecha: Every Sectopod is built not only for self-sufficient commands and operation, but also for psionic manipulation — an Ethereal can control a Sectopod as if it were it's own body from miles away.
- Slow Laser: Both their weapon and vulnerability, even though it's said by the UFOpedia to be a plasma weapon. We can assume that it's really just a different type of laser that's green, leading to your scientists mistaking it for plasma.
- Walking Tank: A massive tank-like machine on two legs, as well as the most dangerous non-psionic unit the aliens have to offer.
The Alien Leader (Unmarked Spoilers!)
The Alien Brain
- Abusive Precursors: During its attempt to reason with you, it claims that the aliens created humanity.
- Big Bad: It controls the alien forces. Its death results in humanity's victory against the alien threat.
- Big "NO!": A rare written example. The alien brain tries to talk you out of killing it via a computer screen at its base. The screen displays an enormous-font "NO" just as the brain is incinerated.
- Brain Monster: A brain big enough to take up four spaces.
- Dirty Coward: When you engage it, it attempts to talk you out of shooting it by claiming that the aliens created humanity and that We Can Rule Together. Your troops hear it out, then shoot it.
- Final Boss: ZigZagged. It is technically the final enemy you have to kill to win the game, but it has no means of defending itself beyond the aliens guarding it.
- The Man Behind the Man: To the Ethereals, who are in turn this to the other races. This effectively makes it the Man Behind the Man Behind the Man.
- Non-Action Big Bad: It is no doubt a devious strategist, considering how difficult trying to stop the alien invasion is, but the Alien Brain has absolutely no methods of defending itself from your soldiers should you manage to reach it.
- Walking Spoiler: In case you couldn't already tell.
- We Can Rule Together: Offers this to your soldiers, who have none of it.
- Zero-Effort Boss: Despite the sheer size of the brain, it doesn't have any psychic powers or weapons, and once all its guards are killed, it's defenceless. You don't even have to fight its guards. Just shoot one of the four tiles it takes up with a Heavy Plasma, and you win.
