The Men in Black
Agent K/Kay (Kevin Brown)
One of the two main protagonists. Just like the film, Agent K is a veteran MIB agent who has served the organization since it was founded.
- Adaptation Dye-Job:
- He's grey-haired in the film, but here in the cartoon he's a brunette.
- He remained grey-haired for the show's first season, but switched to a sort of redhead/brunette mix for Seasons 2 and on, most likely to make him closer match Kay's appearance in the original comic book.
- Age Lift: Sort of. He's still approximately the same age as in the movie, but he looks a few decades younger for some reason - then again, given that it has been established he can control his metabolism well enough to survive almost two hours without breathing, it can be assumed that he can slow down aging as well.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Character Catchphrase: Whenever he and Jay introduce themselves to witnesses, he claims they come from "[Insert organization name], Division 6." In a later episode this is justified as the division of MIB he and Jay are part of is called "Division 6".
- The Comically Serious: Much of his humor comes from his unsurprised reactions to everything about his job.
- Cool Old Guy: A very skilled and experienced veteran agent with quite a reputation for being awesome.
- Deadpan Snarker: With emphasis upon deadpan, much to Jay's annoyance.
- Jerk with a Heart of Gold: He often gives Jay a hard time, but really does care about his well-being.
- Seen It All: Having served the MIB for decades, he's seen a lot of paranormal weirdness and is rarely ever shocked by anything new.
- The Stoic: The animated Kay is even more stoic than the live-action Kay, which is really saying something. He rarely ever shows any emotion on his face.
- Trickster Mentor: He has a rather odd way of teaching Jay how to do things, and sometimes even withholds information from him until later.
Agent J/Jay (James Darrell Edwards III)
The other co-protagonist. Just like the film, he's Agent K's partner, and a naive rookie agent who's still learning how to do his job.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Butt-Monkey: Bad things tend to keep happening to Jay, including everything from Amusing Injuries to genetic mutations. Also, he's not allowed to drive Kay's Ford LTD.
- Character Catchphrase:
- "[Insert organization name], Division 6."
- "I make this look good."
- Crouching Moron, Hidden Badass: He tends to make a lot of serious mistakes, but still proves his worth as an agent all the time.
- Deadpan Snarker: He's just as much a wise-ass as he is in the original film.
- Insistent Terminology: K often calls him "Slick", though he had to "earn" that right.
- Manchild: To an extent. Jay's constant nagging to Kay to allow him to drive the LTD often comes off this way. Also, because Jay is considered the "youngest and most immature" member of the MIB, in one episode he's ordered to go undercover as a teenage student in high school, in order to protect an alien diplomat's son from terrorists (with Kay eventually disguising himself as a substitute teacher, just to supervise both Jay and the boy).
- Naïve Newcomer: As an inexperienced rookie, he's often surprised and confused by what he sees on missions. Even as the series goes on, he doesn't quite change that much.
- Ripple-Effect-Proof Memory: In one episode, due to exposure to a piece of Imported Alien Phlebotinum, he's the only one who realizes that someone is methodically wiping the founders of MIB, and thus the entire organization, out of existence. Unfortunately, the side effects were slowly killing him.
- Spotting the Thread: Agent J is quite adept at spotting inconsistencies in the various disguises and stories aliens put up to hide, enabling him to find the suspicious ones to focus in on. For example, one time he and Elle were driving around the city trying to find a disguised alien ship, and Jay singles out a blimp over Yankee Stadium; when Elle asks why that's suspicious, Jay replies there's no game being held that night. Another time, this almost bit everyone in the behind when he was bait for Alpha. Jay was supposed to be mind probed by Alpha to lure him into a trap where Zed pretended to be retired, but Jay noticed Zed's eyes didn't turn glassy when Neuralyzed, so Alpha realized it was a set up.
- Unresolved Sexual Tension: One episode shows that he literally dreams of having Elle as his girlfriend. But obviously, his crush on her continues to be unrequited.
The current leader of the Men in Black.
- Adaptation Dye-Job: He's a brunette in the film, and grey-haired in the animated series. Though he could be just be a little older. It was even noted in one episode where he admits he used hair coloring but was letting it go natural.
- Age Lift: He looks noticeably older (and fatter) than his movie counterpart.
- Badass Bureaucrat: He was (and still is) a competent agent in his own right, before he became a pencil-pushing administrator.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Cool Old Guy: He may be old and physically unfit, but he can still fight foes such as Alpha.
- Da Chief: The current leader of the Men in Black.
- Deadpan Snarker: Especially to Jay and the Worms.
- Reasonable Authority Figure: He can have a short temper and doesn't tolerate foolishness well, but he's seriously dedicated to his job of protecting humans and aliens alike.
Agent L/Elle (Dr. Laurel Weaver)
An MIB doctor and scientist, and part-time field agent.
- Action Girl: She's just as competent on the field as she is in the lab.
- Adaptation Dye-Job: She was a brunette in the film, and blonde in the animated series.
- Badass Bookworm: Her scientific know-how often helps save the day.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Baritone of Strength: She's as dangerous with alien guns as she is with a scalpel, and with a smooth deep voice to match.
- Be Careful What You Wish For: For three seasons she had been trying to become a full time agent, and she manages to get her wish when she finds a qualified replacement, Unfortunately, that got her partnered with Agent X.
- Hair of Gold, Heart of Gold: Blonde and always courteous to her coworkers.
- Omnidisciplinary Scientist: Equally skilled in medicine, engineering, physics, etc.
- The Smart Guy: The lead (human) doctor/scientist in the organization, until she steps down with Dr. Zeeltor taking her role in the laboratory.
An alien police officer who joins the MIB in Season 4 due to pressure by alien activist groups. He's assigned to be Agent L's partner.
- Adaptation Species Change: There's an agent in the original comics named Ecks, who's human and a rogue agent.
- Anti-Hero: His morals are considerably looser than the other agents.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Blood Knight: He seems to enjoy getting into action and combat for its own sake.
- Cowboy Cop: Impulsive, reckless and insanely gung-ho. L describes him as being less like a "loose cannon" and more like a "megaton bomb". The only reason she's stuck with him is because Zed is giving her a chance to be a field agent, and X was sent by his people as an ambassador, so Zed killed two birds with one stone, but has to deal with their incisive bickering.
- Deadpan Snarker: He makes a lot of unflattering remarks about Earth and humans.
- Fantastic Racism / Politically Incorrect Hero: He openly regards humans as being inferior to his kind.
- Fiery Redhead: Although his true form is completely bald, his Human Disguise includes red hair, which perfectly suits his hot-blooded personality.
- Good Is Not Nice / Jerkass: Tact and politeness are not his strong suit.
- Hero of Another Story: He was a notorious policeman back in his home galaxy, and was awarded for bravery (and suspended for recklessness) multiple times.
- Hummer Dinger: While most MIB agents drive LTDs, X insisted on an SUV.
- Minority Police Officer: He was transferred to the MIB after the Alien Rights Commission complained that the organization only hired aliens as support staff and had no non-human agents, though it is also implied that X's own police force might have wanted him out of their hair due to X being such a Cowboy Cop.
- Sixth Ranger: He's introduced and joins the main cast only in the fourth (and final) season.
The Twins (Idiukupkup and Bob)
Two aliens who help coordinate MIB missions.
- Adaptation Name Change: In the film, Idiukupkup was named Bweryang.
- Aerith and Bob: Idiukupkup and Bob in this case.
- Ascended Extra: They appear for a few seconds in the film, here they are featured more prominently.
- Mission Control: Their job is monitoring MiB operations around the globe.
- Multi-Armed Multitasking: Their alien biology allows them to do more monitoring than a similarly skilled human.
- Starfish Aliens: They have multiple long arms, and their heads are just single eye-stalks.
- The Unintelligible: The audience has no idea of what they say, but Zed does.
- Those Two Guys: Hence "The Twins" instead of their individual names.
Doctor Zandozz Zeeltor
A genius alien scientist who starts working for the MIB in Season 4, replacing Elle as the leader of the science department.
- Amusing Alien: He's a goofy Mad Scientist.
- Gadgeteer Genius: He invents several gadgets for the MIB.
- Mad Scientist: He's certainly rather eccentric.
- Perpetual Smiler: He constantly grins and keeps a cheerful attitude, even when giving bad news.
- The Smart Guy: One of the most brilliant minds in the known universe.
- Sixth Ranger: Like Agent X, he's a newcomer introduced only in the fourth season.
Agent U/You (Upton)
A minor MIB agent who appears occasionally.
- Butt-Monkey: Agents J and K both seem to not like or respect him much due to being a Professional Butt-Kisser.
- Flat Character: He doesn't appear often or get much characterization, beyond being an unimportant joke character.
- Goofy Suit: One of his duties is entertaining and educating alien children as "Oxy the Centipede."
- Hate Sink: His only purpose in the show is to be a boring, unfunny suck-up extraordinaire who the other agents don't like.
- Professional Butt-Kisser / Yes-Man: He's always eager to suck-up to Chief Zed and Agent K.
- Who's on First?: There's a Running Gag in which someone refers to "U", and someone else mishears it as "You".
Four small yellow aliens who frequently hang around the kitchen in the MIB headquarters. They have an overwhelming addiction to coffee.
- Amusing Alien: They're the single greatest source of comic relief in many episodes.
- Hidden Depths:
- When they were fired and set to be deported, they cited a bylaw about how any alien facing deportation can request a tribunal hearing from the MIB. According to K, the rule is "obscure, but on the books."
- They were revealed to be fans of baseball, even holding an annual game, in "The Loose Ball Foul Syndrome." Of course, this fondness for baseball stems from admiration of Joe DiMaggio for popularizing Mr. Coffee.
- Manchild: All of them behave like immature children who can't ever have enough candy (or coffee in their case) and are prone to doing stupid things without ever thinking of the consequences. They even go trick-or-treating in the Halloween Episode, with Agent J supervising them like a reluctant babysitter.
- Must Have Caffeine / Trademark Favorite Food: They are extremely obsessed with drinking coffee, always talking about it and planning to obtain more of it. They say that only royalty is allowed to drink it on their planet, so it's quite a Forbidden Fruit for them.
- The Pirates Who Don't Do Anything: Their exact position within the MIB was never mentioned and they were never shown doing anything outside of one episode where Zed had them keep an eye on MIB's reactor, and even then this was only because the reactor's regular technician had called in sick and no one else was available besides the Worms. It is implied that they were some kind of diplomats, which would explain why Zed put up with their antics, at least until "The Bye-Bye Worm Syndrome."
- Sidekick Creature Nuisance: All of them are quite diminutive, and tend to get on the nerves of other people at MIB (especially Chief Zed, as the Worms like to steal coffee from his office).
- Skewed Priorities: Their efforts to get coffee by any means (including leaving MIB HQ without a disguise) often leads to chaos and trouble.
- Too Dumb to Live: To give one example, when the Worms were assigned to help with maintenance on the MIB's nuclear reactor, they tried using hot water from the cooling system to make coffee. The result was as disastrous as you would expect. Though to be fair, someone already drained 6000 gallons out of it first to sabotage it.
Troy the Symbiote
A young alien creature who left his mother to join MIB as an intern. He needs to be attached to another organism to survive.
- Amusing Alien: Due to being a hyperactive, talkative kid.
- Chuck Cunningham Syndrome: He was made an MIB intern in Season 2, appearing in several episodes before just being dropped without any explanation at all in Season 3.
- Fanboy: He's very fond of Earth's pop culture, especially Hollywood movies.
- Fusion Dance: If he were to be attached to a single host for more than 20 hours, they'll permanently become one. So he constantly jumps from one host to another.
- Healing Factor: Symbiotes and their hosts can regenerate just about any injury. They can also heal others with a touch.
- Motor Mouth: There's rarely a moment when he doesn't have anything to say, and he'll chatter on and on to his hosts.
- Panacea: Symbiotes having amazing healing powers, though they are apparently not completely fullproof, as Troy and his host were shown infected by the alien spores in "The Bad Seed Syndrome."
- The Pollyanna: Always cheerful and optimistic.
- The Symbiote: His species can only survive by living in the bodies of other beings.
- Voluntary Shapeshifting: To an extent. He can't disguise himself as anyone, but can change his host's limbs into weapons and such.
A female alien agent who serves an extraterrestrial organization affiliated with the MIB. And an old colleague of Kay whom he knew "intimately".
- Action Girl: She's a female alien cop.
- Badass in a Nice Suit: Not a member of Earth's Men In Black, but she serves a very similar law enforcement group from another planet.
- Bizarre Alien Biology: She tends to her wounds by pouring orange juice on them after being given a glass of it by K.
- Combat Tentacles: Her fingers are stretchy tendrils that can extend to long lengths, very useful for grabbing and climbing on things.
- Green-Skinned Space Babe: She has blue skin, but otherwise her true body doesn't look much different from her Human Disguise.
- It's Personal: At one point she assists Kay and Jay with recapturing a shapeshifting criminal that killed her previous partner.
- Love Interests: She's an old lover of Kay whom he still has strong feelings for. Jay even notes how Kay acts much less stoic around her.
Frank the Pug
A dog-like alien disguised as a dog. He's frequently a paid informant for the MIB.
- Amusing Alien: Due to superficially resembling a talking dog (especially with his gruff New York accent).
- Ascended Extra: Had a minor role in the movie, but shows up many times in the series.
- Character Catch Phrase: "I only look like a dog!"
- Dude, Where's My Respect?: Both MIB agents and aliens alike treat him like a dog, even when he doesn't need to act like one. It doesn't help that his true form looks similar to his disguise.
- Hidden Depths: He is quite the amateur Egyptologist.
- Hypocrite: Frank is constantly reminding people that he only looks like a dog, and has to act like one to keep the Masquerade. Yet he will continue to act like a dog in places where he doesn’t need to, like MIB headquarters. This includes growling at those who annoy or anger him and scarfing down food. Possibly justified, as he’s been in a dog disguise for so long that he’s stuck in character.
- Jerk with a Heart of Gold: He's mostly out for himself, but shows a kinder, altruistic side every so often.
- Long-Lived: He was still alive a 150 years in the future in "The Future's So Bright Syndrome."
- Lovable Coward: He's lousy at fighting and always tries to flee at the first sign of danger.
- Love Makes You Dumb: In one episode he starts dating a female alien, who's really playing him for a sucker by tricking him into spilling MIB secrets for her mobster boyfriend. Though he does realize his mistakes in the end.
- Paper-Thin Disguise: He reveals what he looks like without his dog "skin," and he looks almost exactly the same except for some antennae and that his paws are more claw-like.
- Pet the Dog: Rather literally; in the Grand Finale, he protects an abandoned litter of puppies and guides them to safety during an Ixion attack on New York City.
- Reformed Criminal: Of sorts. Frank was at least once jailed on another planet for unspecified crimes. And he's rather knowledgeable about the criminal underworld, which is why Kay and Jay frequently use him as an informant. Though unlike Jeebs, Frank isn't (actively) involved in organized crime now.
- Signed Up for the Dental: Why he helps MIB: he gets perks like invites to agent-only rewards in exchange for regular information.
- The Stool Pigeon: When the agents need a lead, they will go to Frank the Pug first.
An alien criminal who runs a black market pawn shop. He's a reluctant MIB informant who often gets his head blown off.
- Alien Blood: He frequently bursts into a puddle of green goo whenever attacked.
- Amusing Alien: Due to constantly receiving Amusing Injuries.
- Arms Dealer: He often sells illegal weapons to various alien criminals passing by his shop.
- Ascended Extra: He plays a greater role in the TV show than the film.
- Blatant Lies: Whenever interrogated by Jay and Kay, Jeebs will claim not to have interacted with any criminals who visited his shop. He's never able to convince them.
- Butt-Monkey: Jeebs will get comically abused and seriously injured Once per Episode, most often with his head being blown up. It goes into karmic territory whenever he's pressed into helping antagonists like Alpha.
- Cain and Abel: The Abel to Dak's Cain. Downplayed because Jack himself is an amoral slimebag, though nowhere near as bad as his brother.
- Character Catch Phrase: "That really stings!"
- Dirty Coward: He'll do anything to save his own skin whenever threatened by others. For example, attacking other aliens when Alpha forcefully demanded that he give him some new body parts.
- Friend in the Black Market: A merchant of illicit goods who's deeply connected to the alien underworld.
- Healing Factor: He instantly regenerates from any injury he suffers, no matter how extreme. This unfortunately drives many characters to shoot his head off constantly as a threat, which according to Jeebs still hurts.
- Heel–Face Revolving Door: As his only true allegiance is to himself, he'll help both the MIB and their enemies, depending on which immediately benefits him more.
- Honest John's Dealership: His store even looks like a typical shady pawn shop.
- Human Aliens: He's not wearing a disguise as far as we can tell.
- Jerkass: He only looks out for his own self-interest.
- Karma Houdini: Aside from all the slapstick abuse he receives, he never faces any real prosecution for the crimes he commits or makes himself accomplice of, even after helping Alpha several times. Presumably because he's just too important as a stool pigeon to be incarcerated or deported.
- Losing Your Head: Happens so often that it's a Running Gag.
- Only in It for the Money: Greed is his main motivation.
- Powerful, but Incompetent: Jeebs is immortal or very nearly so and can regenerate from anything so long as he is in an oxygenated environment, but all of that is moot since Jeebs is so adverse to pain that he never even tries to fight, and while this is understandable when it comes to the likes of the MIB or Alpha, even run-of-the-mill robbers are able to cow Jeebs into submission just by flashing a Ray Gun. His brother, Dak, notably showed just how formidable someone with Jeebs's powers can be if they are not a Dirty Coward.
- The Stool Pigeon: Much like Frank, he often informs the MIB about criminal activity (albeit very reluctantly).
- Would Hurt a Child: Jeebs is afraid of Alpha to the point that he’s willing to kidnap a alien baby in front of his parents, not caring that Alpha will amputate the infant’s arm to replace his own. After his first attempt to abduct the baby failed, he planned to knock him out with a stick. When K learns that Jeebs was the one stalking the family, he lets him know what he thinks about the crime by blasting him in the head the moment he enters his shop.
The monarch of planet Takwalla, which is the homeworld of the Worms. He comes to visit Earth for diplomatic matters twice.
- Adipose Rex: He's both taller and fatter than the other Worms, and he even likes to refer to himself as being "Large and in Charge".
- Aliens Speaking English: Subverted. He tries to speak English, but his grasp of the language is incredibly poor (at one point, the four Worms even ask him to restate what he said in their native language). See My Hovercraft Is Full of Eels below.
- Berserk Button: He doesn't take it well when he catches the quartet of Worms at MIB drinking coffee, because they are commoners.
- Distressed Dude: In his second appearance, he has the misfortune of staying in the same hotel with a much more evil monarch, the Bug Queen, who takes him hostage and attempts to feed him to her young.
- Fat Slob: He was the fattest Worm to appear on the show, and absolutely trashed the hotel room that he was staying in in no time flat in "The Mine, Mine, Mine Syndrome."
- Hawaiian-Shirted Tourist: He disguises himself as a stereotypical "I ♥ New York" tourist in "The Mine, Mine, Mine Syndrome."
- The Good King: He is a bit of a slob, but otherwise appeared to be a decent ruler, seemingly not punishing the Worms and even allowing them to remain on Earth after he caught them drinking coffee, and giving them a grateful hug and seemingly agreeing to their request that they be legally allowed to drink coffee after they helped save him from the Bug Queen.
- Must Have Caffeine: Apparently, coffee is a drink reserved only for himself and other royalty/nobility on his planet.
- My Hovercraft Is Full of Eels: He claims to have learned English from "books on tapeworm", and greets humans with sayings like, "Greetings from my bottom!". The only phrase of English he can speak properly is "I am Large and in Charge."
(Former Agent) Alpha
A rogue MIB agent who once led the organization until he betrayed them. He steals organs from aliens in order to become more physically powerful.
- Bad Boss: To Jack Jeebs, who he often makes an accomplice by terrorizing him. He constantly intimidates Jeebs and has threatened him many times. He is also not nice toward his sentient alien parts, all of whom were maimed and absorbed into him against their wishes. When some of them are finally freed of his body and turned back to normal in "The Heads You Lose Syndrome", they waste no time trying to get revenge on him.
- Bald of Evil: He's balding in his default form, and the little hair he has is gone after his second transformation.
- Big Bad: The most recurring and dangerous antagonist in the series.
- Body Horror: All of his augmentations, both cyborg and biological.
- Broken Pedestal: To Kay, who viewed him as his mentor and friend before Alpha became evil and attempted to kill him.
- The Chessmaster / Evil Genius: He knows everything there is to know about the Men in Black and extraterrestrials, and is quite a cunning mastermind. He even enjoys playing literal games of chess.
- The Comically Serious: He was unaware (until it was pointed out to him) that one of Zed's extracted "memories" was just the ending of Old Yeller.
- Consulting a Convicted Killer: Agents J and K visit him in captivity to ask him about a case suspiciously similar to one he had solved, prior to him turning rogue. K gets tired of Alpha's mind games, but J is much more optimistic, especially since all Alpha wants is for the agents to play chess with him while they question him. Alpha's information proves helpful, primarily because Alpha is actually partners with the alien criminals, and J decides to thank Alpha by giving him a children's electronic chess game to pass his time in prison. K figures out much too late that this was all a massive ruse and, sure enough, Alpha uses the electronics inside the toy to escape prison.
- Cyborg: He becomes this in the final season, deciding that mechanical augmentations are better than biological enhancements.
- Deadpan Snarker: Creepy as he is, he has more than his share of amusing moments thanks to his snarky attitude.
- The Dreaded: Is greatly feared and taken totally seriously by the MIB, with even K being on edge when Alpha is around. He is also feared by aliens, with Jack Jeebs being terrified of him, and often working for Alpha out of fear of him, and even Dak is intimidated by him.
- Evil Brit: As usual with David Warner.
- Evil Former Friend: Was Kay's friend until he betrayed his trust.
- Evil Old Folks: He's an old man, and an irredeemable sociopath.
- Evil Versus Oblivion: In the finale, he fights to stop Vangus from destroying the Earth, since its destruction would leave nothing for him to rule over. Ironically, this gets him killed when he tries to disarm the missile Vangus fired at the planet, since he failed to disarm it in time, and is destroyed along with the missile when J and K blow it up.
- Face Death with Dignity: Downplayed. He is initially calm when he is stuck on the missile Vangus fires at Earth, since at least if he can't rule the Earth, nobody else will. He does have an Oh, Crap! right before J and K blow up the missile, but it's remarkably understated."Oh...not like this."
- Fallen Hero / Face–Heel Turn: The first leader of the MIB, who turned evil.
- Faux Affably Evil: He's always polite and greets Kay as if he's still an old friend. But in reality, he's a cold-blooded and heartless monster.
- Final Boss: Along with Vangus, he leads an Alien Invasion in the Grand Finale episode.
- Humans Are the Real Monsters: Alpha was a normal human whose start of darkness began when he found the Cosmic Integrator and found its possibilities too good to ignore. Even though he slowly becomes a Hybrid Monster by travelling though the galaxy for twenty years, he retains his human mind, which is what essentially drives him to steal and graft alien body parts to himself. Alpha is a symbol of what a human being is capable of if they suddenly gain access to dangerous alien technology, and his actions further justify the MIB's need to keep the secret of aliens.
- Gadgeteer Genius: Generally downplayed due to his primary interests being biological in nature, but Alpha consistently shows a startling degree of skill in the manipulation of almost any technology, whether alien or human. Even when left in a physically decrepit state with little mental stimulation for several months, he manages to escape a maximum security MIB prison cell (part of which is effectively a metal coffin) using the pieces from an electronic chess board.
- Humanoid Abomination: Some of his augmented forms are more so than others, but they are never a pleasing sight.
- Hybrid Monster: He was born human, but has attached so many different alien body parts to himself that he barely qualifies as one anymore.
- Immortality Seeker: He wants to cheat death, and accomplishes this by removing some key organs from aliens with indefinite lifespans.
- Joker Immunity: He was blown up, blown up while in space, knocked down an Antarctic abyss, and blown up while in space again, this time by an Earth-destroying missile. And the video game Men in Black: The Series – Crashdown revealed that he managed to survive even that, and while the game ends with Alpha seemingly being killed again, knowing Alpha...
- Knight of Cerebus: The tone always darkens and the stakes are raised whenever he's present.
- Multiple Head Case: Any alien heads that Alpha integrates into himself still have minds of their own and can even talk, but they are subservient to Alpha.Alien: Hey, I've got a human attached to me! Give me some wart remover!
Alpha: Shut up.
- Organ Theft: His Evil Plans usually involve stealing body parts from aliens. He eventually switches over to robot parts.
- Manipulative Bastard: He secretly toyed with Agent Kay and the rest of the Men in Black, as part of his sinister schemes to steal the Cosmic Integrator and sell out Earth to an alien empire. Much later in the series, he tricks Agent Jay into giving him some improvised tools to escape from his MIB prison cell.
- Pupating Peril: "The Quick Clone Syndrome" reveals that Alpha has been recovering from the injuries he suffered back in his first episode by wrapping himself up in a cocoon deep in the sewers. Having transformed into an even less human shape in the intervening time, he goes on the offensive as soon as J and K begin forcing his cocoon open.
- Screw the Rules, I Make Them!: How he tried to justify using the Cosmic Integrator.
- Smart People Play Chess: To the point that J bribes him to reveal information by allowing him to have an electronic chess board in his cell. Alpha reveals he is even smarter by using it to escape.
- The Sociopath: He's a superficially charming, ruthless manipulator who was respected and trusted enough to become leader of the Men in Black, but had no qualms over backstabbing his own organization (and the rest of his own species), all for the sake of gaining more power. And of course, he doesn't care how many innocent lives it takes to become the ultimate life-form.
- Take Over the World: His ultimate goal in the two-part finale is to enslave any and all surviving humans after the Ixion invasion of Earth is complete.
- That Man Is Dead: According to Kay, "The Alpha [he] knew died 20 years ago."
- Transhuman Treachery: With every alteration he makes to his body, he comes off as becoming less and less human, both literally and figuratively.
- Treacherous Advisor: Used to be Kay's mentor.
A Zombarian police officer turned bounty hunter, who finds and captures other aliens on behalf of his clients.
- Badass Longcoat: A mercenary who wears a Conspicuous Trenchcoat as a disguise, and is skilled and tough enough to fight Agent K to a draw. Though he ditches the coat when he actually starts to engage someone in combat.
- Bizarre Alien Biology: He has three mouths and grasshopper-like, reverse-jointed legs.
- Bounty Hunter: He's an alien bounty hunter who's paid to find and capture other aliens, no questions asked.
- Code Name: "Buzzard"; his real name seems to be Treblor.
- Conspicuous Trenchcoat: Makes his introduction in a noir-like black trenchcoat and fedora hat, complete with a breather mask and facial bandages. This disguise does relatively little to hide his alien features, among other things because he is still toweringly tall and it does not even cover entirely his skin, but it is played for creepiness rather than for laughs.
- Evil Versus Evil: In his first episode, Buzzard was sent to Earth to track down a fugitive criminal. Buzzard lied about still being a cop, was only doing the job for money, and tried to murder Kay for getting in his way. However, he's not nearly as evil as the fugitive he was after — a vicious Serial Killer who eats other sapient aliens.
- Lawman Gone Bad: He served in law enforcement before he found new work as an amoral mercenary.
- Lean and Mean: Freakishly tall (mostly when outstretched, given that he usually has a crouched down stance) and very thin, and definitely not a nice guy at all.
- Lightning Bruiser: Very fast and tough, and can perform high jumps with his long legs.
- Real Name as an Alias: Goes under his former identity as a Zombarian law enforcement agent with his real name.
- Sinister Shades: Wears green goggles over his eyes.
- The Stoic: His reserved demeanor really adds to his overall creepy mannerisms.
- One-Man Army: The guy is dangerous enough to require a literal army to chase him away.
- What Happened to the Mouse?: The last time we see Buzzard in the series, he is zapped away by K. It is unknown if he escaped, or was captured or even killed.
A professional criminal who once shared a prison cell with Frank the Pug. He's a big brute who can shoot fire from his hands.
- Attention Whore: This proved to be his undoing in "The Breaking News Syndrome." Drekk demanded that the alien reality show crew that had been documenting K be present for his showdown with the MIB, and when it looked like he had won, Drekk, egged on by the show's director, got so caught up mugging for the camera and showboating that he got ambushed and taken down by J.
- Ax-Crazy: He wants to burn up anyone who has ever crossed him, preferably by "boiling 'em alive" in a vat of hot liquids.
- The Brute: He's huge, muscular, imposing, and is just as scary as he looks. However, he averts Dumb Muscle.
- Faux Affably Evil: He greets Frank like an old friend, before threatening him due to being a snitch for the MIB.
- Hair-Trigger Temper: He's certainly very hot-headed, both figuratively and literally.
- Jerkass: He's an ill-tempered, violent thug who threatens and throttles even the people he considers friends.
- Not-So-Harmless Villain: He's a dimwitted thug with odd speech patterns, but he's also extremely violent and prone to anger, making him very dangerous.
- Playing with Fire: His hands can shoot out fireballs, and can also burn whatever he touches at will.
Jack Jeebs' evil(er) brother, who briefly worked as a henchman for Alpha.
- Alien Blood: His body fluids are also green.
- Bald of Evil: Dak is revealed to be wearing a toupee when it is sucked into the vacuum of space.
- Big Brother Bully: To Jack, whom he frequently bellitles and blows his head up despite knowing fully well that Jack hates "the sting". When Jay approaches him while disguised as Jack, Dak tries to blow his head up again (which would have killed Jay) despite his brother having a lens he needed, only to be stopped by Alpha, and chooses to pull "Jack" by the ear instead.
- Cain and Abel: The Cain to Jack's Abel. Downplayed because Jack himself is an amoral slimebag, though nowhere near as bad as his brother.
- The Dragon: Serves as this to Alpha during two episodes, helping him against MIB first out of greed and then for revenge after having been defeated by Jay.
- Dragon Ascendant: Dak ends up as Alpha's "partner" after the two end up merged together.
- Evil Twin: Nastier than his brother (though Jack himself is very far from being a saint).
- Fusion Dance: When Dak (and Alpha) are apparently "killed" after the former's first appearance, they accidentally merge into a single being with two heads, much to Dak's dismay. Fortunately they're separated in the end.
- Healing Factor: Being the same species as Jack after all, he can recover from any wounds. His regenerative abilities also apply during the time he's merged with Alpha.
- Human Aliens: Just like his brother, he looks completely human unless splattered into green goo.
- Psycho for Hire: He works as a mercenary, and has no issue working with Alpha or trying to destroy all of the MIB as part of his job, even smiling when it looks like "Tubby" the solar cannon is going to annihilate MIB HQ.
- Revenge: His main motivation in "The Cold Sweat Syndrome" is to get revenge on Jay for having been defeated and blown into space by him.
- Too Kinky to Torture: Unlike Jack, Dak enjoys the pain of having his head blasted off and growing back.
Edmund Clark Moffat
A paranoid conspiracy theorist that turned out to be somewhat right when he accidentally discovered the existence of the MIB. He steals a time travel device to try to wipe the original founders from existence because in his warped mind, if the MIB didn't exist then there would be no aliens on Earth.
- And I Must Scream: It initially looked like Moffat was assassinating the MIB founders, but it turned out that what he was really doing was far worse, trapping them in a Blank White Void outside of time in which they were still fully aware, being shown begging K for help when he was partially sucked into a portal that was opened by Moffat.
- Former Bigot: The ending implies that he ended up becoming one of the founders of the MIB through his own time travel shenanigans.
- Heel–Face Brainwashing: J and K alter Moffat's memories and erase his bigotry before knocking him through a portal to the site of First Contact five minutes before it was set to happen, creating a Close-Enough Timeline in which Moffat helped found the MIB.
- Humans Are the Real Monsters: Moffat was the show's only human villain other than Alpha, and like Alpha he was utterly reprehensible, hating any and all aliens because "Earth is for Earthlings." He was also willing to condemn other humans (who he derisively called "alien lovers") to a Fate Worse than Death to achieve his deranged dream of an alien-free Earth, and while he did get a kind of redemption, it was only due to Heel–Face Brainwashing. J notably saw Moffat as being no different than any other bigot, and even called his actions "hate crimes."
- Irrational Hatred: His hatred towards aliens is almost described as this word for word by Jay. While some wariness of aliens is understandable and obviously some aliens are evil, Edmund's hatred bordered on fanaticism. He truly believed that by destroying the MIB, no aliens would appear on Earth and it never occurred to him that the MIB isn't the reason aliens even come to Earth to begin with. The MIB is a police organization and 99% of aliens that come to Earth do so for reasons that have nothing to do with the MIB.
The Bugs (Drones and Queen)
Giant arthropod aliens, who are the same species as (and directly related to) "Edgar the Bug" from the first film.
- Always Chaotic Evil: All of them are aggressive assholes who want to kill and eat other aliens or humans.
- Big Eater: They constantly crave sugary food and live prey.
- Enemy Civil War: Three bugs came to Earth to capture L for the Queen; all of them are constantly fought each other to get a hold of L.
- Even Evil Has Loved Ones: The Queen is absolutely pissed about Edgar's death, and orders a bounty on Agent L for the other Bugs to claim; she wants them to capture Elle alive so she can be executed by the Queen herself.
- Explosive Breeder: The Queen has millions of offspring. She later decides to move to Earth to infest the planet with her many eggs, and she was able to lay hundreds in just a few seconds.
- Greater-Scope Villain: The Bug Queen was this for the first film and "The Big Bad Bug Syndrome." She finally appeared in-person in "The Mine, Mine, Mine Syndrome."
- Insect Queen: Obviously, the Bug Queen is the leader and mother of all the other Bugs.
- Insectoid Aliens: Of course, they're a whole species of Big Creepy-Crawlies, and they even have a hive-like social structure.
- Killed Off for Real: The Bug Queen is electrocuted to the point of exploding in "The "J" is for James Syndrome."
- Kill It with Ice: They were revealed to an aversion to the cold in "The Mine, Mine, Mine Syndrome."
- Laughably Evil: Much like Edgar the Bug from the first film, they've got a twisted sense of humor around them.
- Older Than They Look: The Bug Queen disguises herself as a preteen when visiting Earth, though is already old enough to reproduce.
- Sibling Rivalry: Not all the Bugs get along with each other. Three different brothers compete to try and kidnap Elle to avenge Edgar's death, only for two of the Bugs to murder the other one. It's stated that this could cause a Civil War among their kind.
- Sweet Tooth: They love sugary food, and eat it by the truck loads.
- Unexplained Recovery: The Bug Queen was frozen and presumably taken into custody by the MIB at the end of "The Mine, Mine, Mine Syndrome." No explanation is provided for why she was active again in "The "J" is for James Syndrome."
A race of aggressive yet diminutive aliens from the planet Fmoo, and sworn enemies of the Arquillians.
- Always Chaotic Evil: All of them are shown to be rather unpleasant.
- Beware the Silly Ones: They may be tiny and rather humorous, but they're still quite troublesome.
- Butt-Monkey: They get abused quite a bit due to being so inconveniently tiny.
- Depraved Dwarf: Just as small as the Arquillians, but way meaner.
- Evil Counterpart Race: To the Arquillians.
- Evil is Petty: They tried to destroy the homeworld of the Arquillians (while making a bunch of them watch) simply because it was slightly bigger than the Fmeks' homeworld.
- Fantastic Racism / Politically Incorrect Villain: Fmeks really hate the Arquillians.
- Laughably Evil: One scene has them comically messing up a threatening warning to Earth.
- Lilliputian Warriors: All of them are militaristic midgets trying to conquer or destroy other planets.
- The Napoleon: They're a whole race of this. One of their schemes involved stealing a growth formula to become as tall (or taller) than humans.
- Verbal Tic: In their final appearance and the video game Men in Black: The Series – Crashdown, they had a habit of adding an "F" to the start of every word that started with an "M."
- Zerg Rush: Their favored tactic.
A leader of the Ixion race, who has been conspiring with Alpha for a planned invasion of Earth for the past 30 years.
- Alien Invasion: His space fleet attacks Earth to seize the planet's oil.
- Bat Out of Hell: Vangus belongs to a bat-like race, with a demonic demeanor to match.
- Big Bad Duumvirate: With Alpha at the end of Season 4.
- Dumb Muscle: The Ixioms are noted to be fierce, but not particularly intelligent, and while Vangus repeatedly displayed cunning, he did largely come off as a brute, even getting one minor comedic moment in which he snorted, "Omelette! Eggs! Good one!" as if it was the funniest thing in the world after overhearing Alpha say, "One can't make an omelette without breaking a few eggs."
- The Dog Bites Back: Alpha treated him with nothing but condescension and practically bullied him, but Vangus got the last laugh when he betrayed Alpha.
- Evil is Petty: Vangus attempts to annihilate all humanity out of what amounts to impatience in the end, rejecting Alpha's suggestion to extract a satisfying defeat for his enemies in prolonged conflict and instead opting to blow up all life on the surface all at once.
- Karma Houdini: Although the Ixion military is defeated by Earth, and Alpha gets killed by Kay and Jay, Vangus himself ends up escaping unharmed, his last whereabouts unknown.
- Knight of Cerebus: Much like Alpha, there is no humor around him, and the threat he poses is more serious than usual.
- Off on a Technicality: He was arrested at the end of his first appearance, but released in his second due to allegations of Police Brutality being leveled against the MIB. It is later revealed that his release was orchestrated by Alpha.
- Planet Looters: He wants to conquer Earth, just because it's rich in oil, which is a valuable resource in the wider universe.
- The Starscream: When the tide of war is turned in Earth's favor, Vangus grows impatient and decides to ditch the idea of letting Alpha rule over the humans, as he prepares to launch a missile that would destroy everyone on the planet while saving the oil for the Ixions.
- Winged Humanoid: He flies around with a pair of wings.