X-COM (Video Game)/Characters

XCOM
XCOM is the Extraterrestrial Combat project, founded by the Council of Nations to fight the aliens.


 * Airborne Aircraft Carrier: XCOM's mobile base of operations in XCOM 2, the Avenger is this. Though technically, it's an old alien transport ship extensively modified with human technology.
 * Badass Army: Eventually, XCOM soldiers can become this, so long as they get back alive after each mission.
 * Elaborate Underground Base: XCOM's main HQ is this in general, no matter where on Earth it's located. In X-Com: UFO Defense, X-COM can have more than one.
 * It's Up to You: In just about every incarnation. Justified in that XCOM is stated to be humanity's first and last line of defence.
 * La Resistance: In XCOM 2, it becomes an underground network and eventually, a vanguard for the Resistance.
 * Multinational Team: It's comprised of scientists, engineers and military personnel from various Council nations, though not exclusively from those countries.
 * NGO Superpower: XCOM is nominally funded by several governments, but if it can get on a roll of looting UFOs and selling their technology, it can earn enough money to become fully independent.
 * Even without achieving monetary independence, XCOM is permitted extremely broad license with only modest oversight -- they launch fighter craft and deploy soldiers well outside of the host nation's chain of command. In Enemy Within, the only unforgivable offence that XCOM can commit is incorrectly accusing a country of being the location of EXALT HQ.
 * No Such Agency: Save for the Council and select groups within the sponsoring countries, no one's really aware of XCOM's existence.
 * Redshirt Army: The HQ's security personnel, aka the ones not sent into combat against the aliens are effectively this.
 * Spell My Name with a "-": In the original series (UFO Defense through Enforcer), the organization's name is spelled with a hyphen ("X-COM"). It is spelled without in the reboot ("XCOM"), although the game logos retain a "negative space" through the "COM" suggestive of a dash.

The Commander
In most of the XCOM games, the player takes on the role of the nebulous "Commander" of XCOM.


 * Featureless Protagonist: In some of the cutscenes in XCOM 2, the player is addressed by the other characters, and the camera appears to be the player viewpoint.
 * Non-Entity General: In most of the XCOM games, the player is referred to by in-game reports and characters, but otherwise has no presence in-game.
 * The Strategist: The commander is (i.e. you are) the strategic mastermind behind humanity's defense against the aliens. Without you, Earth is doomed.  Most of the years leading up to XCOM 2 were apparently spent trying to find you and rescue you from alien captivity.

Central Officer John Bradford
Central Officer Bradford is the main character that XCOM players interact with. He tracks the status of soldiers, missions, and the XCOM agency itself, and reports it to the player.

"Bradford: Are you really using our tracking terminal to play Civilization?! At least I hope you're planning for a military victory."
 * Audience Surrogate: Bradford is not a brilliant scientist like Vahlen, either of the Shens, or Tygan, so they get to explain things to him while we listen in.
 * The Chains of Commanding: He takes the responsibilities that come with leading and sending soldiers to danger - and possible death - very seriously.
 * Drives Like Crazy: Some of the Avenger chatter in XCOM 2 paints him as this, but he says that anyone who has a problem with his flying is welcome to take the helm...
 * Drowning My Sorrows: How he spent a good portion of his time in hiding between XCOM: EU/EW and 2
 * Eagleland: He's very much an American officer. Which is further confirmed in XCOM 2, revealing that he's from Kansas.
 * Hypercompetent Sidekick: As second only to the Commander, aka you, he's effectively this.
 * Memetic Outfit: His green sweater.
 * The Men First: He makes a tremendous effort to make this trope paramount, especially by XCOM 2.
 * Not So Above It All: In one piece of base chatter in XCOM: EU, he has this to say:


 * Older and Wiser: In XCOM 2, given his more sober and grounded composure.
 * Stop Helping Me!: In XCOM 2, he constantly expresses concern whenever the Avatar Project moves closer to completion.
 * Team Dad: By XCOM 2, he's become this to XCOM and implied to be one for Shen's daughter especially.
 * The Watson: In XCOM: EU/EW, much of his dialog is asking one of the doctors to explain what something is.

Dr. Vahlen
Dr. Vahlen is the chief scientist of XCOM in XCOM: Enemy Unknown/Enemy Within. She's quite enthusiastic about getting to research aliens and their technology, and not terribly concerned about the human cost of the missions to retrieve them.

"Bradford: Excellent work, Commander. Our friend here might be uncooperative at the moment, but I have a feeling a talk with Dr. Vahlen will change his tune.""
 * Herr Doktor: Dr. Vahlen's a German scientist with a rather brutal streak and a knack for "interrogating" captured aliens. And she's one of the good guys.
 * Hot Scientist: Downplayed, but she's rather easy on the eyes while staying completely professional.
 * Jack Bauer Interrogation Technique: The peculiar method that's used to "interrogate" captive aliens is of her design. Notably, the interrogation consumes a captive from XCOM's inventory.  A line from Bradford after "retrieving" a VIP (implied to be an EXALT operative) implies that she has experience handling humans as well:


 * Last-Name Basis: We know the first names of the other officers of XCOM, but not hers. The backstory of XCOM 2 however reveals her first name to be Moira.
 * Mad Doctor/Mad Scientist: She's primarily a research scientist, but she is also apparently responsible for overseeing the operations to turn soldiers into MECs, so she must have some medical background.
 * Memetic Molester: Her "interrogations" have helped give her this reputation among fans.
 * Pet the Dog: Occasionally, she'd comment approvingly if soldiers return from a mission unscathed.
 * Stop Helping Me!: She will "helpfully" chide players who use explosives on aliens that she hasn't dissected or interrogated. Presumably, she'd rather sacrifice a few troopers to get the corpses in better condition.
 * Volcano Lair: Apparently, this is where she spent her time between XCOM:EU/EW and 2.
 * What Happened to the Mouse?: Dr. Vahlen's "missing" in XCOM 2, though there are scattered in-game hints that she's still out there.

Dr. Raymond Shen
Dr. Shen is the chief engineer of XCOM in XCOM: Enemy Unknown/Enemy Within.


 * AI Is a Crapshoot: He's not much fond of automated robots, let alone armed ones.
 * Cool Old Guy: Dr. Shen might not be a grandfather, but he definitely exhibits this trope.
 * I Did What I Had to Do: The tone in his voice when XCOM starts deploying MEC troopers suggests this; he doesn't take pleasure in the procedure, but knows it has to be done to fight the aliens.
 * The Heart: He somewhat takes up this role in XCOM, at least compared to Dr. Vahlen.
 * Heroic BSOD: After a while, he loses all interest in acquiring more alien technology, after "seeing enough" of what they're capable of.
 * Heroic Sacrifice: The Avenger in XCOM 2 is implied to be his final masterwork. It's up to the Commander's actions however whether his efforts would be vindicated or all for nothing.
 * The Men First: In contrast to Dr. Vahlen, he's much more adamant in insisting that human lives come first.
 * My God, What Have I Done?: The lengths that XCOM is willing to go to -- splicing humans with alien DNA, or chopping them up into cyborgs -- inspires this feeling in him.
 * Nothing Is the Same Anymore: Dr. Shen brings up how, even if humanity succeeds in fighting off the aliens, there's no going back to the way things were before the invasion.
 * What the Hell Is That Accent?: His accent is vaguely Chinese, though XCOM 2 confirms that he's Taiwanese.

Big Sky
Big Sky is the (callsign of the) Skyranger pilot.


 * Only Known by Their Nickname: Nobody ever calls him anything but "Big Sky."

General Peter Van Doorn
Peter Van Doorn is a VIP who needs rescuing from a Council mission in XCOM: Enemy Unknown. He is very grateful for the rescue and provides some resources as mission rewards.

The mission was not particularly well-liked, but he won some fans with his can-do attitude, even under fire. Popular XCOM streamer Beaglerush named one of his recruits after Van Doorn, and after said trooper became a valuable member of the squad, the Long War developers modified the mission rewards so that he will actually join XCOM after being rescued.

"Bradford: "We're picking up an unsecured transmission from some clown calling himself 'Van Doorn'. Doesn't sound like the kind of recruit we're looking for.""
 * Ascended Extra: He not only becomes a playable member of XCOM in Long War, but also returns as a powerful recruit in XCOM 2.
 * Authority Equals Asskicking: Generals usually don't go to the front lines, but Van Doorn sure can wield a gun.
 * Bald of Awesome: He's got one.
 * Boisterous Bruiser: Even when pinned down by aliens and unarmed, he shouts one-liners like "Get down here! Not fair if I have all the fun!"
 * Determinator: "Come on! I won't go down without a fight!"  In Long War, he comes with the "Implacable" perk that grants immunity to chain-panic.
 * Fearless Fool: In XCOM 2, Bradford gets this impression of him:

The Council
The Council of Funding Nations (X-COM: UFO Defense), Funding Organizations (Terror from the Deep) or "The Council" (XCOM: EU/EW) is a collection of 16 nations that funds the XCOM project.


 * The Alliance: The Council generally comprises major countries from each continent.
 * Black Market: XCOM can discreetly sell alien corpses or scavenged tech to interested Council nations for additional funding. In addition, some Council nations may make requests in exchange for additional funds or staff.
 * Cosmopolitan Council: It includes countries from all inhabited continents.
 * Godzilla Threshold: Such is the urgency of the alien threat that the Council in general is incredibly lenient when it comes to collateral damage. So long as XCOM gets the job done.
 * Government Conspiracy: A rather benevolent example. In its Enemy Unknown/Enemy Within incarnation at least, the Council makes an effort to both conceal the full extent of the alien threat and XCOM's existence from the public. This is largely to maintain some semblance of stability and allow XCOM to do its job.
 * Les Collaborateurs: Countries will defect if they think XCOM isn't doing a good enough job, and in XCOM 2, it is revealed that every member (save the Spokesman) is subsumed into ADVENT.
 * NGO Superpower: In TFTD, the Council includes some corporations (which still correspond geographically to the countries they replace).
 * Not-So-Omniscient Council of Bickering: When XCOM does poorly and panic mounts, the response of the Council nations is to cut funding, leaving XCOM even less capable of tackling the alien threat. Should panic get high enough, nations will leave the Council, and if enough of them leave, it's game over.
 * United Nations Is a Super Power: Averted. The Council is independent of the UN. In UFO Defense, it was said to have been founded during a secret meeting in Geneva.

Council Spokesman
In XCOM and XCOM 2, the "Council Spokesman" is the specific individual who provides XCOM's evaluations and funding reports.


 * Catchphrase: "Hello, Commander" and "Remember, we will be watching."
 * Do Not Go Gentle: He makes a point to encourage the Commander and XCOM to keep up the good fight against the alien threat, and later on, ADVENT.
 * The Faceless: He is always lit from behind, to shadow his face. We know that he's bald, and that's it.
 * Guttural Growler / Badass Baritone: He upgrades to the latter when.
 * La Résistance: He's a central figure of the Resistance in XCOM 2, the only member of the Council still loyal to humanity.
 * Mysterious Backer: The whole Council are mysterious backers, but he's the only one the player sees. He's also the only one who sticks with the resistance in the 20 years leading up to XCOM 2.
 * Reasonable Authority Figure: He consistently demonstrates how incredibly forgiving and understanding he can be, given the nature of the alien threat and later on, helping the Resistance. XCOM would have to really screw up for him to even express disappointment.
 * Reverse Mole: In XCOM 2, he's also serving this role within ADVENT. It's strongly implied that he holds a relatively high position.

EXALT
EXALT is a mysterious organization added as part of XCOM: Enemy Within. They are a rogue human faction dedicated to causing trouble for XCOM and using the alien invasion to forward their own goals.


 * Ancient Conspiracy: They certainly dress the part in HQ, with decadent art and artifacts all over the place.
 * Cyanide Pill: When stunned, EXALT operatives will stab themselves with some sort of poison syringe. (Their grenades and laser guns can still be retrieved, if they have any.)
 * Faceless Goons: In addition to business suits, all EXALT operatives wear a regulation orange bandana over their faces.
 * Fallen Hero:
 * Fan Nickname: "Eggsalt." In vanilla, they're less of a threat than the aliens, and their ragdolling gives them a sense of clumsiness.
 * Foil: To XCOM. They've got a headquarters with a hologlobe, but they're seemingly composed of businessmen and civilians rather than military personnel.
 * Hidden in Plain Sight: How EXALT largely manages to elude detection. Even its HQ can pass for a corporate executive office, albeit a rather decadent one.
 * Not So Stoic: EXALT operatives drop the radio-garbled noises when they panic.
 * Les Collaborateurs: It's hard to say. The Council introduces them as harboring "misguided sympathies" for the aliens, but they later steal Annette from the aliens. In Long War, alien pods can include EXALT operatives.
 * Ragdoll Physics: EXALT operatives tend to ragdoll pretty spectacularly when killed, often getting flipped over whatever they were using as cover.
 * Take Over the World: What EXALT hopes to achieve, especially with governments around the world and the Council busy dealing with the alien threat.
 * The Unintelligible: To further dehumanize them, EXALT speech consists of growly radio-static noises. The exception is when they panic: they'll yell "I'm losing control of the situation!"
 * Transhuman Treachery: EXALT goes much further in enhancing its operatives that even Dr. Vahlen is disgusted.
 * Weaksauce Weakness: Hacking their radio towers causes them to be unable to fire their weapons. Elite and Heavy operatives can still throw grenades or shoot rockets, though, so don't get too cocky!

The Bureau
Formally known as the Bureau of Strategic Emergency Command, it is the titular organization of The Bureau: XCOM Declassified. A covert paramilitary and intelligence force set up by the U.S. Government in 1962, it's the first organization to use the name "XCOM."


 * Cold War: The Bureau was originally set up to counter Communist activity and sustain "continuity of operations" in the event of a Soviet invasion. As the 1960s alien invasion went underway, its Director, Myron Faulke quickly retooled it to combat the threat.
 * Deliberate Values Dissonance: Site X, the Bureau's Elaborate Underground Base is rife with cigarette smoke.
 * Enemy Mine: Eventually, the Bureau brings in a Soviet infiltrator on the belief that the aliens pose a mutual threat. This in turn foreshadows XCOM's later Multinational Team aspect.
 * Necessary Evil: Some of the shadier actions done by the Bureau are justified as this.
 * No Such Agency: Only a handful of people in the U.S. Government even know of the Bureau's existence. In addition, the Bureau also tries to mask the alien invasion (and keep the public calm) by passing off the aliens' communications jamming efforts as an emergency test.
 * Origin Story: It's the predecessor of XCOM.
 * Renegade American: With the chain of command disrupted thanks to aliens' interference, the Bureau increasingly behaves independently while still purportedly serving the U.S. Government.
 * Sharp-Dressed Man: Bureau operatives are either this or donning Vietnam-esque fatigues.
 * Start of Darkness: Given some of the shadier and murkier antics done by the Bureau, this could be foreshadowing.
 * Unperson: The Bureau's M.O. In addition to fighting the aliens, its operatives were tasked with erasing civilian casualties from the records. Even burning entire towns attacked by the aliens if necessary.

Annette Durand
Annette Durand is a pre-made recruitable character introduced in XCOM: Enemy Unknown/Enemy Within, who's rescued in a Council mission. It's gradually revealed that she's been sought after by both the aliens and EXALT for her latent psionic abilities. Abilities that she can willingly use for XCOM.


 * Action Survivor: Annette is initially presented as this. Once she joins XCOM however, she graduates into being a potent soldier relatively quickly.
 * Blood Knight: She seems to really enjoy killing aliens.
 * Everyone Looks Sexier If French: Downplayed, but she's pretty and French.
 * Gratuitous French: Averted. Even as part of XCOM, she still prefers to use English, albeit with a noticeable French accent.
 * Heroic Resolve: Seeing an XCOM squad wipe out a whole mass of aliens upon rescuing Annette convince her that the aliens could be beaten.
 * Mauve Shirt: She's a "hero character," but is otherwise killable just like everyone else.
 * Mildly Military: Justified in that unlike most other XCOM personnel, she was just a civilian before getting involved in the whole alien and EXALT mess. As a result, she tends to be less formal and occasionally complain about military protocol.
 * Squishy Wizard: She's shown to be a very powerful psi-user. But is otherwise an ordinary human.

Shaojie Zhang
Shaojie Zhang is a pre-made recruitable character introduced in XCOM: Enemy Unknown/Enemy Within, who's rescued in a Council mission. He was a member of the Triads, but contacted the Council when his boss started dealing in alien technology.


 * Asian Speekee Engrish: Averted. He has a noticeable Chinese accent but has no trouble speaking English whatsoever.
 * Badass: He manages to headshot a Sectoid with a conventional pistol in his intro cutscene.
 * Enemy Mine: He turns on the Triads and joins XCOM after realizing that his cell's latest "merchandise" is alien technology.
 * Magic Knight: His high Will makes him a good psionic soldier, and he's got higher aim and health than the average soldier as well.
 * Mauve Shirt: He's a "hero character" with better-than-average stats, but is otherwise killable just like everyone else.
 * The Triads and the Tongs: The Triads, to be precise.

Dr. Richard Tygan
Dr. Tygan is the chief scientist by XCOM 2, taking the place of Dr. Vahlen. He had previously been an up-and-coming researcher for a pharmaceutical corporation before ADVENT took over.


 * Admiring the Abomination: Dr. Tygan is most impressed by some of his findings regarding ADVENT technology and the aliens. As times passes however, it starts giving way to horror as he realizes just how far the aliens are willing to go.
 * Badass Bookworm: He performed a surgical procedure on himself in order to remove a brain chip ADVENT implanted before joining XCOM.
 * Defector From Decadence: He used to work for ADVENT and enjoyed the creature comforts that came with being a researcher in the Gene Clinics. Until the true nature of ADVENT finally began dawning on him.
 * For Science!: Dr. Tygan doesn't particularly approve of Dr. Vahlen's more brute methods. But even he admits that there's a thrill in working under the tense conditions XCOM tends to operate under.
 * Heroic BSOD: As much as he tries to downplay it, he's unnerved and disgusted by the revelations of the Avatar Project.
 * Omnidisciplinary Scientist: Subverted. His knowledge and expertise is wide enough that he can conduct research into various fields, but knows well enough about his own limitations to leave certain autopsies and finds for Shen to tackle.
 * Red Herring Mole: Although more than a few in XCOM still harbor some concerns on whether he's really defected to the good guys,.

Chief An-Yi "Lily" Shen
Lily Shen is the daughter of Dr. Shen from XCOM, filling his role as Chief Engineer.


 * Badass Bookworm: She's shown to test new weapons like plasma guns by firing them herself.
 * The Engineer: Much like her father, she's very handy with creating various equipment and weapons.
 * Generation Xerox: She's taken quite a bit from her late father.
 * Legacy Character: Twenty years after XCOM, there's a new Chief Shen in the workshop. Though her conversations with the Commander reveal that she still misses the long-dead Dr. Shen.
 * Missing Mom: We have no material whatsoever on Mrs. Shen.
 * Robot Buddy: She's created one in the form of a customized GREMLIN. When she and Dr. Tygan try using said GREMLIN, she's none too happy to see the results.
 * The Workaholic: Lily's shown to be constantly working, believing that time not spent doing something productive is time wasted. It's also implied to be her way of coping with all the death and chaos around her.

Sectoid
In the original X-COM and in XCOM: Enemy Unknown/Within, Sectoids are the basic grunts of the aliens. They're not particularly strong, but their plasma weapons are no joke against rookies and they do have some psionic talents, which develop as the game progresses. In XCOM 2, they've been made much tougher with the addition of human DNA.


 * Boss in Mook Clothing: Sectoid Commanders look nigh identical to regular Sectoids, save for a different color. But they have significantly more hitpoints and more psionic power, making them a challenge for even a veteran squad.
 * Fan Nickname: "Ayys." After their more muscular forms were revealed for XCOM 2, they were also nicknamed "Pectoids."
 * The Greys: Sectoids are basically these -- in fact, if the Roswell incident really was an extraterrestrial UFO encounter in the XCOM universe, they might actually be the Grays of conspiracy lore.
 * Mooks: They're the alien equivalent of these.
 * Powered Armor: Mechtoids, which are essentially Sectoids fused into these. While significantly tougher and with much more potent firepower, they lack their brethren's psionic capabilities.
 * Took A Level In Badass: The Sectoids become significantly more powerful in XCOM 2, thanks to genetic enhancements.

Viper
Introduced in XCOM 2, Vipers are the "true form" of the Thin Men deployed in the initial invasion. Now that the aliens openly run the world, there's no need to blend them with human DNA to infiltrate; they can just strut (er, slither) in their full reptilian glory.


 * Demonic Spiders: Very much so in the early game. They can dodge attacks (thus taking reduced damage), yank soldiers out of cover and bind them in their coils, and spit clouds of poison, making them considerably harder to handle than ADVENT troopers.
 * Ensemble Darkhorse: Once she slithered into the gameplay demo, players were smitten.
 * Fan Nickname: "Snek."
 * Non-Mammal Mammaries: To be fair, the Vipers are not from Earth, so they could be mammals after all. Their breasts might not necessarily be mammary glands, either.

Muton
A foe from the original X-COM as well as XCOM: Enemy Unknown/Within the humanoid Mutons are the aliens' shock troopers and heavy infantry. Genetically modified for military purposes, they make up for their lack of psionic abilities with heavy firepower, keen intellect and a fierce zeal to their masters. They also serve as a basis for other alien types, like Floaters and Berserkers.


 * Proud Warrior Race: It's suspected that the Mutons or their original predecessors were this before being genetically modified and enhanced. Elements of this can still be found, however, through their "blood calls" and tribal markings.
 * Elite Mooks: Muton Elites, powerful, heavily armored guardians who are generally around whenever there's an Ethereal on the battlefield.
 * Evil Counterpart: Mutons in general have been described by Word of God as akin to an alien SEAL Team Six
 * Took a Level In Badass: By XCOM 2, Mutons have become more streamlined, but no less dangerous.

Thin Man
Introduced in XCOM: Enemy Unknown/Enemy Within, the Thin Men are aliens intended to be infiltrators and scouts for the invasion. As such they're meant to look, dress and act like humans from a glance. XCOM 2 reveals the Thin Men as heavily modified Vipers, and it's implied that "perfected" versions of them are still around working with ADVENT, such as the Speaker.


 * Acid Bath: Their guns seem to be loaded with this. In addition, killing a Thin Man results in an explosion of corrosive acid.
 * Demonic Spiders: Compared to Sectoids, they can come across as this for a good portion of the game.
 * Face Death with Dignity: Unlike the other alien types, the Thin Men refuse to cower before their impending demise in Dr. Vahlen's "interrogations."
 * Glamour Failure: Bits and pieces of their original, reptilian selves are still visible in their snake-like eyes (hidden by shades) and the scales on their necks. Not even the "perfected" version seen in XCOM 2 managed to remove those flaws entirely.
 * The Men in Black: Their general appearance is based on this, complete with shades, dark suit and tie.
 * Uncanny Valley: While a Thin Man can pass off as human from afar and can speak in different Earth languages, it doesn't quite work. Especially given their size and unnaturally fluid movements.

Ethereal
The Ethereals are the leaders of the alien invasion force. They are masters of genetic manipulation and psionics, and have already brought several species under their control. Humanity is their next goal.


 * Blue and Orange Morality: The Ethereals are revealed to follow motivations, principles and morals that fittingly come across as alien and abhorrent to mankind.
 * Dying Race: For all their psionic talent, the Ethereals are physically frail. Humanity has the potential for psionic powers and physical strength, so they want to use our genes to improve themselves.
 * Man Behind the Man: The Bureau: XCOM Declassified, which involves a different alien invasion in early-1960s America.
 * Not So Stoic: They try to act like they're above it all, but even they show fear when being interrogated by Dr. Vahlen.
 * Squishy Wizard: Their psionic powers are incredibly powerful, but are so physically weak that they can get gunned down with relative ease once they're targeted. Which is why they tend to come with a group of Elite Mutons to protect themselves.
 * The Gloves Come Off:

ADVENT Trooper and Officer
Introduced in XCOM 2, the human forces serving ADVENT are a common sight and willingly follow their alien masters' diktats. Even if this means turning on their own compatriots.


 * Alien Blood: One of the first signs that something's off about ADVENT forces in general is that they bleed orange.
 * Authority Equals Asskicking: ADVENT Officers are noticeably more competent than the rank-and-file.
 * Elite Mooks: Later on in XCOM 2, Elite variants of ADVENT forces start getting deploying, with considerably more armor and aim.
 * Evil Counterpart: To XCOM after a fashion. They even come in different classes like Lancers and Shieldbearers.
 * Les Collaborateurs: ADVENT soldiers seem to be this, given they're apparently human volunteers.
 * Magnetic Weapons: Unlike the actual aliens, ADVENT forces exclusively use these.
 * Mecha: ADVENT MECs, which are completely automated or at least remotely controlled.
 * Mooks: They're the XCOM 2 equivalent of them.
 * More Than Mind Control: While ADVENT soldiers are generally loyal to a fault, the aliens augmented them with certain psionic-based enhancements to further coordinate them.
 * Sincerest Form of Flattery: In addition to being based on the aliens' Sectopods, ADVENT MECs are suspected to be also derived from XCOM's MEC Troopers in Enemy Within.
 * Starfish Language: They all speak in an alien language, making it difficult to discern what they're going to do.
 * Transhuman Treachery: ADVENT soldiers are extensively enhanced.

Sectopod
First introduced in the original X-COM, Sectopods are the aliens' main Humongous Mecha, being large bipedal AI robots bristling with various weapons. They're also heavily armored and a single one can wipe out whole squads by itself. By XCOM 2, they've been given even more upgrades by the aliens and are also used by ADVENT to keep the populace in line.


 * Boss in Mook Clothing: Though they're not technically bosses, they come across as one thanks to their firepower and armor. Especially if a squad's unprepared.
 * Demonic Spiders: Not necessarily the Sectopods themselves, but the enemies that tend to accompany one. Whether it's robotic Drones in Enemy Unknown/Enemy Within or ADVENT Shieldbearers in XCOM 2.
 * Humongous Mecha: In all its incarnations; they can even bypass if not outright destroy cover just by walking. XCOM 2 takes this further, with Sectopods having extendable legs, making them even taller.
 * Interface Screw: In XCOM 2, it's almost guaranteed that a Sectopod is nearby when the game's interface starts glitching up due to its movements.
 * Made of Explodium: Destroying a Sectopod will damage if not kill anyone/anything close to it when it explodes.
 * More Dakka: Sectopods come with a variety of weapons, from close range lasers to squad-killing missiles.
 * Retroactive Continuity: An earlier version of the Sectopod, which is "piloted" by a Sectoid mind in contrast to the fully automated robots found elsewhere in the series, is used during the 1960s invasion as seen in The Bureau: XCOM Declassified.
 * Shout Out: By XCOM 2, they're more reminiscent of the Tripods from The War of the Worlds.

Chryssalid
The Chryssalids are the aliens' archetypal "terror units", deployed against civilian centers to sow discord and panic. Their sole tactic is to race up to humans, savage them in melee, and then implant eggs in their corpses. This results in a zombie (X-COM: UFO Defense, XCOM: Enemy Unknown/Within) or a cocoon (XCOM 2), which then results in more Chryssalids...

Every X-COM game has had enemies which can multiply from humans, but the Chryssalids were the first.


 * Bizarre Alien Reproduction: Chryssalids require large host organisms to incubate their eggs and gestate.
 * Demonic Spiders: Chryssalids are "only" capable of making melee attacks, but their extreme mobility more than makes up for it. They're especially horrible on Terror missions, where they can quickly multiply from the civilian population.
 * Face Full of Alien Wing-Wong: The fate of those killed by Chryssalids.
 * Fan Nickname: "'Lids". The oversized boss "Chryssalid Queen" from Long War is sometimes nicknamed "Queen Sally".
 * Retroactive Continuity: In XCOM 2, Chryssalids don't lay eggs in corpses or spawn zombies; instead, their attacks leave a "Chryssalid Venom" status ailment, and anyone who dies while subject to that debuff will produce a cocoon, which will produce three Chryssalids if not destroyed. Bradford refers to the zombie phenomenon as a rumor from the early days of the invasion.