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.
- 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.
- Badass in a Nice Suit: Being one of The Men in Black after all.
- Catchphrase: Whenever he and Jay introduce themselves to witnesses, he claims they come from "[Insert organization name], 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.
- 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.
- "[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.
- 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-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.
- 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.
- 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.
- Hair of Gold, Heart of Gold: Blonde and always courteous to her coworkers.
- Hot Scientist: Jay certainly sees her this way.
- Omnidisciplinary Scientist: Equally skilled in medicine, engineering, physics, etc.
- She's Got Legs: Her skirt is about knee-length.
- The Smart Girl: 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.
- 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.
- Aerith and Bob: Idiukupkup and Bob in this case.
- 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.
- Fun with Homophones: There's a Running Gag in which someone refers to "U", and someone else mishears it as "You".
- Professional Butt-Kisser / Yes-Man: He's always eager to suck-up to Chief Zed.
Four small yellow aliens who frequently hang around the kitchen in the MIB headquarters. They have an overwhelming addiction to coffee.
- Amusing Aliens: They're the single greatest source of comic relief in many episodes.
- Ascended Extras: They only appeared in one scene in the first movie, but they're frequently recurring characters in the cartoon.
- Manchildren: 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: It's implied that they're employees of the MIB, but all they do most of the time is just drink coffee in the kitchen. Apparently they lied to their Emperor about serving the MIB as elite agents.
- Skewed Priorities: Their efforts to get coffee by any means (including leaving MIB HQ without a disguise) often leads to chaos and trouble.
- Small Annoying Creatures: 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).
- 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.
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 stops appearing after the first couple seasons.
- 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.
- 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 extant. 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.
- 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 Interest: 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.
- Catchphrase: "I only look like a dog!"
- Jerk with a Heart of Gold: He's mostly out for himself, but shows a kinder, altruistic side every so often.
- 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.
- 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.
- 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.
- Catchphrase: "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.
- HeelFace 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.
- Losing Your Head: Happens so often that it's a Running Gag.
- Only in It for the Money: Greed is his main motivation.
- The Stool Pigeon: Much like Frank, he often informs the MIB about criminal activity (albeit very reluctantly).
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 call 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.
- 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.
- 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.
- 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.
- Cyborg: He becomes this in the final season, deciding that mechanical augmentations are better than biological enhancements.
- Evil Brit: As usual with David Warner.
- Evil Former Friend: Was Kay's friend until he betrayed his trust.
- Fallen Hero / FaceHeel 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.
- 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 it more than others, but they are never a pleasing sight.
- Hybrid Monster: He was born human, but has attached so many different alien body parts 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: At the end of each of his appearances, he is seemingly killed in action or otherwise defeated, but only to return again and again to cause more trouble. He finally meets his actual demise in the final episode, when Agents J and K blow him up with an intercepted missile.
- Knight of Cerebus: The tone always darkens and the stakes are raised whenever he's present.
- Organ Theft: His Evil Plans usually involve stealing body parts from aliens.
- 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.
- Screw the Rules, I Make Them!: How he tried to justify using the Cosmic Integrator.
- Smart People Play Chess: To the point 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 towering tall and it does not even cover entirely his skin, but it is played for creepiness rather than for laughs.
- Evil vs. 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.
- 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 a ruthlessly violent criminal with a very short temper after all.
- 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.
- 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.
- 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.
- Too Kinky to Torture: Unlike Jack, Dak enjoys the pain of having his head blasted off and growing back.
The Bugs (Drones and Queen)
Giant arthropod aliens, who are the same species as (and directly related to) "Edgar the Bug" from the first movie.
- Always Chaotic Evil: All of them are aggressive assholes who want to kill and eat other aliens or humans.
- Big Eaters: They constantly crave after sugary food and live prey.
- Even Evil Has Loved Ones: The Queen is absolutely pissed by 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.
- 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.
- Laughably Evil: Much like Edgar the Bug from the first film, they've got a twisted sense of humor around them.
- 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.
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 Monkeys: They get abused quite a bit due to being so inconveniently tiny.
- Depraved Dwarfs: Just as small as the Arquillians, but way meaner.
- Evil Counterpart Race: To the Arquillians.
- Fantastic Racism / Politically Incorrect Villains: 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.
- Zerg Rush: Their favored tactic.
A leader of the Ixion race, who has been conspiring with Alpha for a planned invasion of Earth since the past 30 years.
- Alien Invasion: His space fleet attacks Earth to seize the planet's oil.
- Big Bad Duumvirate: With Alpha at the end of Season 4.
- 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.
- Bat Out of Hell: Vangus belongs to a bat-like race, with a demonic demeanor to match.
- 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.
- 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.