"I want to have friends, and hang out like normal teenagers do! But who would want to hang out with a rusty hunk of metal like me?"
The main protagonist and the "16-year-old robot" (built 5 years ago) to which the title refers, a state-of-the-art sentient gynoid automaton created by Dr. Noreen Wakeman five years prior to the series, though she was designed as a 16-year-old girl. Though XJ-9 was designed to be Earth's protector, armed to the teeth with a wide range of weapons, devices, and transformations, she wants to live the life of a normal teenager and often makes this desire quite apparent to her friends and creator.
- Action Girl: A ridiculously powerful crime-fighting robot.
- Adorkable: When she gets acquainted with the real world for the first time.
- The Ageless: Since Jenny is a robot, she'll look like a teenager forever, though she does seem capable of maturing mentally. She even has a dream of hanging out with her classmates when they're in the retirement home and she looks no different than the present.
- Ain't Too Proud to Beg: Typically to her mother when she don't get her way.
- All of the Other Reindeer: No matter what she does, she will always somehow end back up as the school freak.
- Animesque: Her character design, just look at her!
- Artificial Family Member: Even though Nora Wakeman created Jenny to protect the Earth, she was still treated like a daughter.
- Badass Adorable: A One-Man Army shaped like a cute robot girl.
- Balloon Belly: She has inflated more than once, despite being made of metal.
- Bare Your Midriff: Jenny's design is meant to give this impression, with blue plates at her chest and waist mimicking a tank top and a miniskirt. A screw in the center mimics a belly button.
- Beware the Nice Ones: Her temper is incredibly human, all things considered. Combine that with a Hyperspace Arsenal, and you get literally-explosive anger.
- Big Sister Instinct: Jenny is rather protective of Tuck, and generally treats him like her was her little brother. His screaming even helped her when Fighting from the Inside.
- Bifauxnen: Some of her outfits, such as in "Grid Iron Glory", a select few in "Victim of Fashion" and her persona as Ruby Rocket in "Girl of Steal" make her an occasional example.
- Blue Is Heroic: Her body is white with blue paint on the parts that resemble hair and clothing.
- Blush Stickers: When she blushes, she displays blue-colored ones.
- Born as an Adult: This issue is addressed in the episode "I Was a Preschool Drop-out" when XJ-9 is forced to attend preschool after the authorities find out she has only been active for five years. The later episode "Humiliation 101" had Nora reveal to Jenny's classmates that, while she came online with an adolescent body, she still had an infantile mind and was even strapped to a baby's highchair.
- Bratty Teenage Daughter: She sometimes acts like a disobedient teenage delinquent to Dr. Wakeman.
- Butt-Monkey: She suffers misfortunes quite a bit, the worst offenders including "Ear No Evil" (where she is ceaselessly mocked for her goofy-looking ears) and "Killgore" (where the title antagonist keeps pestering her and she's unable to fight back without being seen as cruel by the people who adore Killgore).
- Catch-Phrase: Crikey!
- Cool Loser: It's hinted that if the school weren't under the tyrannical reign of two Alpha Bitches, Jenny wouldn't be a reject at all.
- Curtains Match the Window: Her hair and outfit colors match.
- Cute Bruiser: Built like a teenage girl and a super robot that regularly pummels monsters into the crowd.
- Cute Machine: Just look at her, she's a total sweetie!
- Deadpan Snarker: Started developing into sardonic banter by season two.
- Demonization: Subverted In-Universe; Queen Vexus of Cluster Prime demonizes XJ9, presenting her like an Always Chaotic Evil, horrible monster robot that wants to destroy her own kind in various propaganda videos showed to the robots. When XJ9 accidentally goes to Cluster Prime, all the robots see her for the cute, normal, heroic robot who wants to help and protect others. Even when someone recognizes her and the Robot police try to catch her, she is helped by her new friends. This leads to Queen Vexus downfall. There is also the fact that the propaganda doesn't bother showing her true appearance, allowing Jenny to remain Hidden in Plain Sight.
- Dented Iron: She may be tough but she has her limits. Many times she gets beaten up to the point where she can hardly fight.
- Destructive Saviour: Often causes buildings to get destroyed when she fights monsters.
- Ditzy Genius: A highly advanced and intelligent combat android. But she's pretty clueless and naïve when it comes to mingling with non-robotic teens.
- Do-Anything Robot: Her arsenal is downright Hammerspacey.
- Does Not Know Her Own Strength: Jenny has some initial problems fitting in due to this, but eventually gets used to her surroundings. At home, she seems to have either figured out how to lounge around without breaking stuff, or Dr. Wakeman has simply reinforced a lot of the house.
- Early Installment Character-Design Difference: In the original Oh Yeah! Cartoons pilot short, her hands were the same coloring as her hair and "clothes", she had lips, and her skirt had rivets on the bottom.
- Fem Bot: She's a female robot built with a feminine shape.
- Genki Girl: She's quite excitable and with a positive attitude.
- Girlish Pigtails: She has metal protrusions on her head shaped like pigtails. She stores a rocket in each which she uses to fly, and they've been shown with other strange functions like antenna, blades, and ears.
- Girly Girl with a Tomboy Streak: She's has a love for clothing, pretty boys and shopping, and has an overall feminine demeanor, but she's also a proud Action Girl loaded with weapons whose friends are mostly male.
- The Heroine: The series revolves around Jenny who was created by her mother, Dr. Nora to protect Earth.
- Hero with Bad Publicity: Despite saving the world multiple times, the citizens of Tremorton still treats her like garbage.
- Held Back in School: Jenny is sent to kindergarten on one occasion because she is technically only 5 years old.
- Huge Schoolgirl: She's stated to be 6' 6".
- I Just Want to Be Normal: Combined with I Just Want to Have Friends: Being a superpowered robot wouldn't be so hard for her if there were more bots as advanced as her.
- Jerk with a Heart of Gold: She often shifts between this and Nice Girl, depending on whether the episode is making liberal use of Surrounded by Idiots.
- Jet Pack: Not so much as one as a flying robot, as she has rockets as part of her body. She can also transform herself into one.
- Light Is Good: A white robot and The Heroine.
- Lightning Bruiser: She possesses super strength and speed.
- Loves My Alter Ego: Jenny just considers Sheldon her friend, but falls in love with Silver Shell almost immediately (despite Sheldon trying to make him as repulsive as possible so she'd dislike robot guys). Eventually, he dates her as the Silver Shell, but she ends up hating him because he keeps sneaking off (to hide that their dance was being crashed by the space bikers) and Sheldon decides he'll have better luck with Jenny as himself.
- Magical Girlfriend: The components of the fantasy are all there; Sheldon, the Nerd Loser Protagonist, falls in love with the Super Heroine Fembot who saves him from bullies, and becomes her Dogged Nice Guy. Too bad she's not interested (although Word of God says that she would have become his girlfriend if the series had continued).
- Magic Skirt: Justified, as that "skirt" is made out of metal and is actually her pelvis.
- Meaningful Rename: Calling herself "Jenny" reflects her desire to be seen as a teenager rather than a machine. Nora usually calls her XJ-9, except during heartfelt moments.
- Omniglot: She has software that apparently allows her to speak any language, though we just see her speaking English and Japanese.
- Pinocchio Syndrome: Averted - she's perfectly fine with being a robot, but wants acceptance and assimilation... which sometimes means playing the trope straight.
- Platonic Life-Partners: With Brad. In fact, Jenny is just about the only girl who Brad doesn't show any kind of interest in or who shows any interest in him.
- Ridiculously Human Robot: Jenny thinks, emotes, cries, sleeps, and eventually dreams like a human. About the only humanlike thing she can't do is eat anything besides oil.
- Robot Girl: An American twist on the trope: Jenny is less interested in saving the world than hanging out with high school kids.
- Robot Hair: She sports a pair of metal pigtails. They house two of her jet thrusters.
- Single Woman Seeks Good Man: She's sick of smooth operators, and wants someone sweet and sincere. Sheldon walks by, and she greets him, still wondering where she can find someone like that. There are hints that Jenny will eventually pick Sheldon. Confirmed by Word of God after the series' cancellation.
- Sliding Scale of Robot Intelligence: Average Joe: Emotionally, she's basically like a human teenager—which is to say she can be very mature or very childish depending on the situation. Intellectually, it seems to vary by the episode whether she's a lot smarter than most humans, or basically just like a human with a built-in calculator.
- She Cleans Up Nicely: Who knew that a teenage robot got a spa from greasy gearheads in order to visit Don Prima's party and in one episode, dresses herself in a variety of fashions to outdo the Crusts?
- Slapstick Knows No Gender: She tends to suffer more injuries than the rest of the cast.
- Statuesque Stunner: She's 6 1/2 feet tall (though this seems to include her hair) and really cute to boot.
- Stripperiffic: She wears a very small tanktop with a miniskirt, showing off a large amount of her body. Granted, it's made out of metal.
- Super Strength: "The strength of a million-and-seventy men," if the theme song is to be taken literally. note
- Telescoping Robot: She provides the trope picture.
- Wake Up, Go to School, Save the World: Pretty much her daily life, though the school bit is new.
- Weaksauce Weakness: Water tends to fry her circuits or rust her skin.
- What the Hell, Hero?: In "Escape From Cluster Prime" her irresponsible handling of the Cluster Bomb causes an Earthquake which angers the whole town. In "Weapons of Mass Distraction" she refuses to fight crime because she's on a date, which backfires when her date calls her selfish for doing so and breaks up. In "Mist Opportunities" Sheldon calls her out for slacking off and letting Misty be the town's savior, despite Misty's shady character, and in "No Harmony with Melody" Brad calls her out for trying to kill Melody, who she mistakenly thinks is a villain.
- Younger than She Looks: Technically has been alive for about 5 years, but has all the mentality of a teenage girl... usually. Jenny being physically five years old was even played as a joke, where a truant officer threw her into Kindergarten for the majority of the episode "I was a Preschool Dropout".
Jenny's best friend and next-door neighbor.
- Action Survivor: He's a completely normal human, but he helps Jenny take on intergalactic threats regularly, and even sometimes joins her on the front lines.
- Adorkable: Considers himself to be smooth and charismatic, but is really just an awkward, lovable teen.
- Anime Hair: He has three large spikes in his hair. He uses a lot of hair gel to get it that way.
- Badass Normal: No super powers to speak of, but still occasionally manages to be useful in battle.
- Camp Straight: Brad is rather metrosexual, but shows exclusive (and frequent) interest in women.
- Casanova Wannabe: Brad frequently insists he's irresistible to the ladies, which always causes any girl present (but Jenny) to turn their nose up at him.
- Chick Magnet: While Brad's game with human girls is pretty dire, he seems to have no problem attracting the attention of aliens and robots. Pretty much none of it is wanted.
- Cool Loser: Brad has a fairly cool demeanor and a decent fashion sense, but is implied to be pretty low on the social ladder.
- Crouching Moron, Hidden Badass: His over-enthusiasm for trying to be a hero can be more trouble than help, but when he gets serious he can be a pretty reliable ally.
- Distressed Dude: His gung-ho attitude frequently results in him needing to be rescued.
- The Face: While he's nowhere near as popular as he thinks he is, Brad is quite charismatic, and is able to function in social situations where Jenny can't.
- Fearless Fool: Tends to leap headfirst into action despite almost always being way out of his depth.
- Fiery Redhead: He has dark red hair and is quick to leap before he looks.
- Foil: To Jenny. While Jenny is super-powerful, but extremely self-conscious and would rather be a normal teenager, Brad is an ordinary guy who is extremely self-assured and desperately wants to be anything but a normal teenager.
- Glory Seeker: Brad's primary goal in life is to be popular. He doesn't care what form this popularity takes, and pursues becoming a sporty jock, a famous musician and a world-saving superhero with equal amounts of enthusiasm.
- I Just Want to Be Special: In contrast to Jenny's desire to be a normal teen, Brad wishes that he could be a super hero, which causes him to tag along to help her fight evil frequently.
- Interspecies Romance: Brad seems quite prone to this, considering his short relationship with Melody and his implied relationship with Misty.
- The Load: Particularly in earlier episodes, he tends to only get in the way or get captured when he tries to help Jenny out. Pretty much averted later on, as he pulls his weight much more consistently.
- Muggle Best Friend: He's an ordinary human who is best friends with a super-fighting robot.
- Nice Guy: Brad is typically a very friendly, upbeat person.
- The Not-Love Interest: He's Jenny's best friend and usual foil, but their relationship is entirely platonic.
- Platonic Life-Partners: With Jenny. In fact, Jenny is just about the only girl who Brad doesn't show any kind of interest in or who shows any interest in him.
- Redheads Are Uncool: Isn't too popular at his school.
- Ridiculously Average Guy: Though he wishes to be more.
- Small Name, Big Ego: Brad thinks of himself as a cool, charismatic social butterfly as well as an accomplished adventurer. In reality, he's a clumsy, unpopular teen who thinks too highly of himself.
- Took a Level in Badass: After training in the Skyway Patrol, he becomes more consistently reliable during action sequences.
- Unfazed Everyman: Generally handles supernatural encounters with a combination of neutrality and enthusiasm.
- Weirdness Magnet: The supernatural and the extraterrestrial seem to be naturally drawn towards him.
Brad's little brother.
- Annoying Younger Sibling: Tuck can sometimes be annoying, mostly because he's such a scream queen, though it doesn't seem to hurt his popularity in-universe. Brad even claims, when talking about Kilgore and Tuck, that "annoying + small = popular".
- Badass Adorable: He knows almost as much as Dr. Wakeman about robots.
- Cheerful Child: Tuck is very enthusiastic and smiles almost constantly.
- Distressed Dude: Even more than his brother.
- Jerk with a Heart of Gold: Depending on the Writer, he's either a self-centered brat or a well-meaning kid who has trouble understanding boundaries. Sometimes at the end of the episode, he does something unselfish, other times he doesn't learn anything.
- Kid-Appeal Character: Despite being a kids' show, the main cast is almost entirely teenagers, so Tuck fills in the much-needed role of a kid character.
- Karma Houdini: In several episodes his selfishness causes destruction and pain for the main heroes, but he gets off relatively free.
- Kids Are Cruel: His treatment of Jenny, Sheldon, and Brad can get downright brutal.
- Lack of Empathy: One of his major flaws, Depending on the Writer. He regularly takes advantage of and humiliates his friends like in "Tuckered Out" and "The Boy Who Cried Robot" and shows little regard for their safety like in in "Histrionics". In "Ball and Chain" he doesn't care about his brother being forced into a marriage with a fish monster, only seeing it as an opportunity to have adventures in space.
- Large Ham: He's got quite a pair of lungs for a little guy and puts them to use.
- Lovable Coward: He's the most likely to start running and screaming in any situation.
- Only Sane Man: Slides in and out of this if the situation calls. Conversely, in a few episodes he's a pushy jerk.
- Taking Advantage of Generosity: A few episodes have been based on Tuck abusing Jenny's protective nature or his friends' general wishes to help him because he's younger. This generally doesn't end well for him.
- Wholesome Crossdresser: He wears a dress and a necklace in "Labor Day".Tuck: What? Can't a guy wear pearls and taffeta around here?
Nora: Strictly speaking, only after 6.
Dr. Nora Wakeman
An elderly spinster robotics scientist and the one who built the XJ robots, who is often simply refers to as "Mother" or "Mom" by Jenny and her sisters.
- Action Mom: When in danger, she shows no reluctance in fighting.
- Amazingly Embarrassing Parent: Anytime Nora talks to a peer of Jenny besides Brad and Tuck, expect to her some embarrassing detail about Jenny's design or maintenance.
- Cool Old Lady: She even fought Vexxus with her bare hands!
- Defrosting Ice Queen: Was once very, very strict about Jenny's lifestyle and initially desired to keep her out of the public eye when not fighting evil. She eventually comes around however to embrace Jenny's very humanlike nature and now lets her live as the typical teenage girl she designed her to be, allowing Jenny to interact freely with humans.
- Gadgeteer Genius: She's built incredibly powerful Ridiculously Human Robots as well as other machines.
- Genki Girl: She comes off as a lively and excitable woman. No surprise where Jenny gets it from.
- Early Installment Character-Design Difference: She had a different hairstyle and her clothes were completely white in the pilot short on Oh Yeah! Cartoons.
- Einstein Hair: Her hair is white, spiky and messy
- Gag Nose: While it isn't pointed out often, in The Movie Sheldon calls her a "birdnose" and later she uses it to poke Vexus' eye.
- Mad Scientist: One of the saner ones, but some of her inventions and experiments seem to serve no clear purpose.
- Mama Bear: Jenny is certainly a powerful robot who can take care of herself, but that won't mean that Nora will tolerate anyone threatening Jenny while she's around. Especially since she's a Retired Badass
- Maiden Aunt: She is an unmarried aunt to her nephew, Glenn Wakeman, though both Wisteria and Nora are Truly Single Parents.
- Meddling Parents: One episode had her remove Jenny's ability to hang-up on her
- Motherly Scientist: Jenny calls her "mom" and Dr. Wakeman certainly does view her as her daughter.
- Never Mess with Granny: She used to be part of the Skyway Patrol prior to the series. Even in present-day she's far from any definition of "weak".
- Older Than They Look: She looks old enough to have grandchildren; she also has a de-aging machine which shaves decades off with each use. The casual air with which she mentions this implies it's been used many times.
- The Professor: She created Jenny and tends to provide her with upgrades and gadgets of her own design to help Jenny take on tough opponents.
- Sibling Yin-Yang: With her sister, Wisteria. While Nora has a scientific, logical and mechanical view, Wisteria is more based on nature and was a flower child with potential mystic elements. Also telling in their children, Nora's robot daughter and Wisteria's Plant Person son, Glenn.
- Shipper on Deck: When Nora first sees Sheldon and everyone is assuming he's Jenny boyfriend, she immediately expresses approval, mostly because he's a gangly scientist-type like her.
- Truly Single Parent: Nora considers XJ-9 her daughter (the other XJ robots somewhat less so), and despite Brad and Tuck always calling her "Mrs. Wakemen", she's never been married.
Sheldon Lee/Silver Shell
Jenny's self-proclaimed romantic admirer.
- Abhorrent Admirer: Towards Jenny at first, Subverted as he mellows out of his stalking in later episodes and she starts to enjoy his company.
- Ace Pilot: He's shown to be capable of flying alien spaceships competently.
- Adorkable: He is quite geeky, but he is a very kind, if somewhat awkward, towards Jenny. And that's what makes him quite endearing.
- Agent Peacock: When he joins the secret agency, his code name is "Baron Von Fashionista III".
- Ambiguously Bi: In one episode he has a conversation with Jenny discussing which members of a Boy Band is the cutest.
- Asian and Nerdy: While his ethnicity isn't confirmed in the show, his surname suggests an Asian background and the Japanese citizens shown have similar skin tones and facial features as him.
- Awesome, but Impractical: He likes to go about things in a needlessly complicated way. In the beginning of "Shell Game", he uses a gun-like gizmo which extends small appendages to open a soda bottle just so he can use the bottle cap with which to hit Jenny, distracting her long enough for him to stand before her. Yeah.
- Big Brother Instinct: They're not related, but he was very protective of Tuck in "A Pain In My Sidekick", trying save him from enemies and crying when he thought Tuck might have died at the end of the episode.
- Butt-Monkey: Suffers quite a bit over the course of the series.
- Chivalrous Pervert: Towards Jenny. It may seem sometimes that he's only interested in Jenny's robot abilities and design, but in other episodes proven otherwise. For example, once Jenny wanted him to remove all her equipment, and he complied (although reluctantly) and spent hours on end removing all of it despite knowing how she would look afterwards.
- Clark Kenting: Despite rather blatant evidence that Silver Shell is him (the similar names, it's just a "shell" he pilots, and the head crest that looks like Sheldon's hair), no one ever suspects this.
- Crouching Moron, Hidden Badass: Despite frequently prat-falls and his nerdy appearance, Sheldon eventually shows himself to be rather competent, managing to sneak past the Wakeman's security system, help Nora board a Cluster warship, live as space pirate (eventually a captain) for decades, and even spent a while as a secret agent.
- Deuteragonist: Later in the series, he's arguably more in-focus than anyone but XJ-9 herself.
- Distressed Dude: Though this becomes less frequent later on.
- Dogged Nice Guy: Several times his sincere and friendly attitude have gotten Jenny's affection, only to lose it because of a misunderstanding or because Jenny found out something very unpleasant that he'd done recently.
- Dude, Where's My Respect?: It's not that he can't ever get any respect, but he has to work much harder for it.
- Forgotten Phlebotinum: Sheldon treats the Silver Shell suit only as a means to get closer to Jenny. He never thinks of using it for anything else, like defending the Earth from the Cluster when Jenny is MIA in the movie. After Jenny loses her infatuation with the Silver Shell, he only uses it once more, when Tuck finds the thing in his garage.
- Gadgeteer Genius: He's created functioning Power Armor, his own robots (though nothing as human-like as Nora's), new gadgets for Jenny to use, and a functioning time machine.
- Hates My Secret Identity: Sheldon creates the superhero identity of Silver Shell so Jenny will date him (and to convince Jenny to date him for real). It eventually backfires when she gets frustrated with the Shell and traps Sheldon in a web of lies.
- Hero-Worshipper: A variant in that he's smitten with XJ-9 as well as seeing her as a role model.
- In Touch with His Feminine Side: Sheldon's not exactly a masculine type, and he has interests in Fashion Magazines and Boy Bands.
- Interspecies Romance: Sheldon's crush on Jenny.
- Large Ham: As the Silver Shell, he has melodramatic and hammy dialogue to play up his being a superhero.
- Older Than They Look: The events of "Good Old Sheldon" ended with him physically 15 years old, but 105 chronologically and mentally—and he remembers all of it.
- Only Sane Man: At times. In "Mist Opportunities" he's the only one to call out Jenny for letting Misty be the town's hero, despite the first time she showed up she left the Earth when it was under attack because she felt like it. In "Historionics" Jenny and Brad were infatuated with Wizzly, but Sheldon reminds them that Wizzly's animatronics were trying to kill them.
- Rescue Romance: Sheldon meets and falls hard for Jenny after she saves him from some bullies in shop class.
- Robosexual: He's a human who has a crush on Jenny, a robot. Vexus uses this to her advantage in "Designing Women", wherein she disguises as a robot girl to distract him long enough to get the XJ 9 blueprints he stole from Nora. It works.
- Single-Target Sexuality: Jenny is the only person he's attracted to.
- Stalker Shrine: He has an unsettlingly large colletion of pictures of Jenny in his closet and his locker.
- Stalker with a Crush: In his introduction episode he was definitively this, but in later episodes he is more friendly and helpful towards Jenny.
- Strong, but Unskilled: As the Silver Shell his fighting style is rather sloppy but the suit is strong enough for him to last.
- Throw the Dog a Bone: a few episodes end up well for him. In the Christmas special Jenny finally gives him a kiss. She gives him another in "Agent 00' Sheldon" although starts attacking when she found out he was spying on her. Also in "The Price of Love" it's revealed in 20 years he'll become a billionaire.
- Took a Level in Badass: Started off as a meek nerd who could barely defend himself against bullies. In later episodes he's much from being a space pirate captain to a secret agent. Go figure.
- Undying Loyalty: In the Christmas episode, he's the only person to stay by Jenny's side when the entire town has turned against her by this point.
- What Does She See in Him?: Not Sheldon himself, but Jenny is infatuated with his alter-ego the Silver Shell. Sheldon deliberately acted like a jerk to turn Jenny off dating robots, but it backfired. In later episodes Jenny would get irritated enough at the Shell because of his obnoxiousness, but continues to admire him the next time he appears.
- Yank the Dog's Chain: There are a few moments where he comes close to gaining Jenny's affection only for it to be ruined in the last moment due to a misunderstanding or his prior actions biting him in the ass.
XJ-9's prototypes and "sisters".
- Big Little Sister: XJ-8 is much larger than Jenny despite being considered her younger sister. She is technically also older (which would make XJ-1 the Little Big Sister), though Jenny seems to have spent the most time online.
- Break Out the Museum Piece: Once, after Jenny got captured by the Cluster, she sent out an emergency beacon that reactivated them. With the exception of XJ-8 they don't appear to be combat-ready, but do okay as they apparently have the same telescoping armor Jenny does.
- Combining Mecha: Not exactly in a true "mecha" sense, but they do have the ability to join together to form various weapons along with the "Robo Wall".
- Cute Clumsy Girl: XJ-3 constantly trips and falls apart.
- Cyber Cyclops: XJ-3 has one physical eye that sits on top of her body while XJ-6 has a computer display face that shows one eye.
- The Eeyore: XJ-7 is constantly depressed, even lamenting that she couldn't destroy herself properly.
- Flawed Prototype: All of them. Unlike most examples of the trope, though, they are clearly functional testbeds that do well within the parameters of their design.
- Frickin' Laser Beams: XJ-2 is basically a laser gun with legs and eyes.
- Green-Eyed Monster: Everyone word XJ-6 says is complaining about someone else, usually Jenny, getting more attention than her. Bonus points for her eye actually being green.
- Hiccup Hijinks: XJ-2 constantly hiccups, causing her to misfire.
- Machine Monotone: XJ-8 speaks like this, though the tone changes depending on the episode.
- Motor Mouth: XJ-5 sounds like a used car salesman and never, ever stops talking. Justifiable in a sense; from the look of her eyes and her speaker mouth she may have been constructed using parts from a radio, and radios NEVER stop broadcasting.
- Neat Freak: XJ-4 compulsively cleans everything she sees.
- Ridiculously Human Robots: The XJ sisters appear to be gradually working towards this. May also be why XJ-8 isn't the last in the line.
- Sliding Scale of Robot Intelligence: Most of them are Average Joe like Jenny, but XJ-1 and XJ-2 are closer to Robo-Monkeys, being like a human baby and toddler, respectively. XJ-8 is also a lower-level Average Joe than the rest, being very blunt and thuggish.
- Super Prototype: XJ-8 is physically stronger than Jenny—to the point that she's really not looking forward to fighting her—but doesn't have Jenny's "quirk and charm" according to Dr. Wakeman. Being so terrible at talking to people still makes her a Flawed Prototype even in terms of being a superhero, as she, for instance, thought children breaking a pinata were committing a crime.
The tyrannical queen of the Cluster who constantly tries to get Jenny to go with her to her homeworld of Cluster Prime through immoral means.
- Arch-Enemy: Vexus to Jenny, and vice-versa. Vexus isn't even happy with conquering Earth unless Jenny is there to see it.
- Attention Whore: She's devolved into this by season 3. After losing her planet, she's overjoyed at the idea of being adored by everyone at Tremorton High.
- Bad Samaritan: She claims to be a liberator of machines, though her definition of "liberation" is merely a sugar-coated "assimilation into our collective".
- Be Careful What You Wish For: Spends most of the first and second seasons trying to bring Jenny to Cluster Prime. And what happens when she actually gets there?Cluster Prime: Down with Vexus! Down with Vexus! Down with Vexus!
- Bee People: She has a lot of queen bee motifs.
- Big Bad: As the leader of the Cluster, Vexus functions as the main villain of the series.
- Bitch in Sheep's Clothing: She'll figuratively (and often literally) put on the guise of a human being or fellow robot to give off the impression of a good samaritan when she's the exact opposite.
- Break the Haughty: She eventually loses her dictatorship over Cluster Prime, reducing her to a madwoman living on a garbage planet and talking to the creatures crawling around it. She's mostly back to normal by the end of the third season and menacing Jenny as usual, though without her empire behind her, she's significantly less of a threat.
- Broken Pedestal: Toward her daughter Vega, who never believed she was downright evil. Upon learning the truth, she helps Jenny overthrow her own mother.
- Determinator: Not even losing her entire planet and empire will deter her from attempting to destroy Jenny, and humanity by extension.
- Even Evil Has Loved Ones: She does care about her daughter, to the point the latter considers her overbearing.
- Evil Matriarch: Of Cluster Prime and the empire as a whole
- Fantastic Racism: Doesn't like humans very much, even labeling them "flesh wearers".
- Faux Affably Evil: She is usually polite to Jenny, even while trying to destroy her or assimilate her into the Cluster.
- Galactic Conqueror: Being the leader of an interstellar robot extremist empire bent on enslaving the human race, she certainly qualifies.
- God Save Us from the Queen!: Cluster Prime's residents are actually good-natured, but misled by Vexus' propaganda that paint Jenny as a horrid monster.
- Hive Queen: If her queen bee motif didn't give it away, she's the head of a collective of bug themed robots.
- How the Mighty Have Fallen: After losing her empire in season 2, she's much less of a threat without her army behind her, and even devolves into insanity at one point. She gets better, but it hardly helps that she is still alone in her endeavors against Jenny.
- Hypocrite: She and the Cluster in general insist humans are unjustly controlling Earth's machines, yet she's quite the tyrant herself, and will gladly use mind control to force those same machines to join the Cluster, willing or not.
- Join or Die: Her general philosophy when it comes to assimilating robots into the Cluster.
- Laser-Guided Karma: Being a deceptive tyrant who tries to force Jenny to join the Cluster and enslave humanity, it's only fitting that she loses her entire planet in the process.
- Manipulative Bitch: She relies on cunning and subterfuge to accomplish her goals. One notable example, is her using Sheldon to acquire Jenny's blueprints for herself, so as to predict her weapons and counter them effectively. And that's not even getting into her propaganda campaign to keep her subjects ignorant of her true nature, while demonizing Jenny.
- Not So Different: For someone who despises humanity and boasts about robot superiority, she herself possesses some of their worst traits, being a dictator and all.
- Overarching Villain: She is present for the entire show, appearing every season and always hatching some scheme to enslave humanity.
- Revenge Before Reason: In "Trash Talk" she plans to blow up the planet Jenny is on, despite being on the planet herself and not having a viable way off.
- Sanity Slippage: In "Trash Talk" she becomes noticeably more insane, planning to blow up a planet she's on and escaping on a pod that can only fit a hamster. She gets better by "Queen Bee".
- Take Over the World: Pretty much her entire plot in a nutshell.
- Totally Radical: She would have blended in while she was destroying Jenny if she only realized that The Roaring '20s was over for almost a century now.
- Tsurime Eyes: Her eyes are slanted upwards.
- Villainous Breakdown: She remains fairly composed for most of the series, but she really starts to lose it when Jenny turns her entire planet against her rule. By the time of "Trash Talk", she's been reduced to madness, trying to use some random scraps of garbage to build an escape pod and referring to Krackus and Smytus with nonsensical names.
- Villain Decay: As the head of the Cluster Empire, Vexus was the biggest threat of the first two seasons. In the Escape From Cluster Prime special, she loses everything; her armies, her planet, and even her own daughter's turned against her. She later turns up in season 3, stranded on a junk asteroid and gone insane. While she regains her senses later on, she's nowhere near as threatening without her empire behind her.
- We Can Rule Together: She makes this offer with Jenny, trying to get her to help her robot brethren and destroy the human race. You can guess what Jenny's answer was.
A large green robot from the Cluster who seems to have ties to its military division.
- Badass Baritone: He has a deep, booming voice provided by Steve Blum.
- Badass Boast:Brad: We can do it! We can stop them! We haven't met a robot yet we can't destroy!
Smytus: Then you haven't met me!
- Bad Boss: His answer to one incompetent minion causing him to lose the Pip crystals? Throw his entire crew out the airlock.
- Big Creepy-Crawlies: In keeping with the Cluster's bug-theme, Smytus resembles a large rhinoceros beetle.
- Bond Villain Stupidity: His Fatal Flaw, complete with Evil Gloating, 10 second countdowns, the whole set.
- The Brute: He serves as the physical driving force of the Cluster's army. When it comes to Jenny, Smytus employs force, in contrast to Vexus' subtlety.
- Card-Carrying Villain: If his "DESTROYER OF WORLDS!" speech is anything to go by, he really enjoys being a villain.
- The Dragon: As commander of the Cluster's military, Smytus serves as this to Vexus.
- Dragon Their Feet: Vexus is defeated at the climax of Escape From Cluster Prime, but Smytus is still menacing humanity on Earth, threatening to destroy the planet. He doesn't get very far when Jenny re-enters the picture.
- Dude, Where's My Respect?: In his first appearance, he laments that Vexus gives him demeaning nicknames.
- Evil Gloating: Thanks to his ego, he will engage in this any chance he gets.
- Evil Is Hammy: As demonstrated with Incoming Ham below, he has the subtlety of a sledgehammer to the face.
- Evil Laugh: Goes hand in hand with his Large Ham. He's very fond of these.
- Evil Sounds Deep: Not as deep as some of Blum's other roles, but still pretty low-pitched.
- Fantastic Racism: Like the rest of the Cluster, he doesn't hold "fleshbags" in very high regard.
- Half the Man He Used to Be: After blowing himself up at the end of Escape From Cluster Prime, Smytus is reduced to a torso, and is forced to walk on makeshift legs cobbled together from junk.
- How the Mighty Have Fallen: By season 3, he's lost his armies, his status, his pride, and half his body. Revenge is the last thing on his mind; he just wants his legs back.
- Hyper-Competent Sidekick: Smytus becomes this for Vexus in Escape From Cluster Prime. Vexus is too caught up in her vendetta with Jenny to properly lead the invasion, and abandons it altogether upon learning she's on Cluster Prime, leaving Smytus to carry it out himself. He succeeds in squashing the human resistance and enslaving the population, only to settle for blowing up the planet when they defy him. He would have succeeded, too, had Jenny not returned in the nick of time.
- Incoming Ham: "Bow to me, mortal, and tremble in fear! Before you stands Smytus, lord of the outer rims, mayor of moon robia, cappo of the cram nebula, and DESTROYER OF WORLDS!" (cue Dramatic Thunder)
- I Just Want to Have Friends: Played with. He perks up quite a lot when he's complimented by the humans, and he has to remind his minions to laugh with him after he makes a hammy speech.
- Large and in Charge: He's bigger than most of the established Cluster villains, and is their military commander.
- Laugh with Me!: He has to order his minions to engage in an Evil Laugh with him... like they mean it.
- Meaningful Name: Smytus sounds like it's derived from "smite," meaning "to defeat and/or conquer," which fits his occupation as a conquering warlord.
- Near-Villain Victory: Has came close to winning at least twice.
- He'd successfully assimilated Jenny, along with 7 of the other XJ-sisters, and was about to have her destroy her own mother... until XJ-1 barfed in her face, snapping her out of it.
- In the special, he nearly destroyed the planet in Jenny's absence, until he was foiled again by her timely intervention.
- Not Quite Dead: He seemingly perished at the end of Escape From Cluster Prime when he activates his self-destruct, but later shows up in season 3... Half the Man He Used to Be but alive nonetheless.
- Paper-Thin Disguise: He puts on a wig and tries to pass himself off as Smytlana, a Ukrainian supermodel. After a short while of being complimented, he falls for the disguise himself.
- Self-Destruct Mechanism: He has one literally stored up his sleeve. Of course, it comes with a ten second countdown, as well.
- Small Name, Big Ego: Although he's the commander of the Cluster military, he doesn't appear to garner much respect from his superiors. Best example comes from when the Crusts shrink him and he's left scrambling while boasting about his status as a Cluster champion.Smytus: I am a warrior! I am a destroyer of worlds!
- Smug Snake: Credit where it's due, Smytus is a capable villain, but he often overestimates his abilities and indulges in gloating far too often, which just as often bites him hard.
- Sore Loser: Has some shades of this. Main example comes from when the XJ-sisters are able to free Jenny from his control, and he almost throws a tantrum.
- Surrounded by Idiots: His opinion of the drones under his command.
- Taking You with Me: With his ship, armies, and robot factories in ruin, Smytus activates his self-destruct to destroy Jenny and take as many humans with him as possible, as a final act of defiance and spite. It doesn't work quite the way he intended, as said self-destruct came with a ten second countdown, giving Jenny time to stop him..Smytus: Not so fast, XJ-9. You may have destroyed my mega-weapon, and my ship, and my robot factory, and my troops, but I still have an ace up my sleeve. Literally! Self-destruct, baby! Every supervillain's last resort! Say goodbye to your beloved fleshbags! This ends now... in ten seconds!
- Top-Heavy Guy: One of, if not the strongest of Vexus' minions with stumpy legs.
- Uncertain Doom: Smytus, Vexus, and Krackus were all present on the garbage planet when it blew up. Since Vexus returns later on, it's possible Smytus and Krackus survived as well, and may have reappeared had the series continued.
- Villain Ball: He gives his self-destruct sequence a countdown, allowing Jenny enough time to throw his ship into orbit right before it explodes. Woops.
A senile, older Cluster robot who often bungles his experiments and forgets where he is all the time. His inventions almost never last for very long, but he's not one to give up easily.
- Beware the Silly Ones: He may be an old coot with a failing memory, but he's still a capable inventor. Like what Nora tells her daughter, "Don't underestimate him! Sooner or later he may invent something that actually works!"
- Big Creepy-Crawlies: He bears a resemblance to a large beetle or cockroach.
- Bungling Inventor: He's pretty clumsy and most of his inventions fall apart after being used once.
- Evil Genius: He's the brains of the Cluster, though everyone else believes otherwise.
- Evil Old Folks: A crackpot inventor with a few screws loose, but one of the Cluster's top inventors.
- Informed Flaw: He's treated as a joke by most characters, but his inventions largely work as intended.
- Miniature Senior Citizens: He's the shortest member of the Cluster seen before the Big Damn Movie.
- Not-So-Harmless Villain: He's called one of the most incompetent members of the Cluster, even getting laughed at. Yet most of the time, his inventions work as intended and he is a legitimate threat.
- Only Sane Man: In "Trash Talk" he's the only one who wants to use Jenny's fuel to power a spaceship to get off the trash planet, whereas Vexus is completely off her rocker and wants to blow up the planet (despite having no way off), and Smytus wants to get a new pair of legs, regardless of the fact that he'd still be stuck on the planet.
- Robot Hair: Has a metal mustache that also functions as a mouth in imitation of a beetle's mandibles.
- Uncertain Doom: Krackus, Smytus, and Vexus were present on the garbage planet when it blew up. While Vexus was shown to survive, it's unknown what happened to Krackus or Smytus.
A small, adorable wind up robot from a toyline, Killgore somehow managed to attain sentience and decides to fulfill its purpose as a villain, first by joining the Cluster and capturing Jenny, then by destroying the Cluster and Jenny. Things don't always go as planned for him, however.
- Badass Adorable: He managed to outsmart Jenny twice and rebuild Armagedroid, who is millions of times Killgore's size.
- Bratty Half-Pint: He drives Jenny bonkers in his debut by virtue of pestering her to "SURRENDER!"
- Catchphrase: Surrender and "BA-NAH!"
- Card-Carrying Villain: Killgore insists you read his tag!
- Cute Is Evil: He's considered the cutest thing ever in-series, and a Card-Carrying Villain through-and-through. Jenny's biggest problem with facing him is that she can't fight back without people hating her for it.
- Deathbringer the Adorable: Sure the name may sound threatening, but it's so gosh-darn cute!
- Determinator: To his credit, he's persistent. He spends most of his debut annoying Jenny into submission.
- Enemy Mine: With Jenny in "Enclosure of Doom".
- Evil Sounds Deep: Spoofed in the first few seconds of the episode he's introduced, as it's not wound up yet.
- Expy: Seems to be one of Invader Zim. He's a short hammy non-human with a high pitched voice and speaks in Third-Person Person who wishes to please an intergalactic Evil Empire by destroying mankind while having delusions of grandiose. He causes grief for the main hero, but nobody else seems to care for his villainy.
- Harmless Villain: To the point where he was outright rejected by the Cluster. But he does somehow manage to enlist the help of ''Armagedroid'' in his second episode.
- Ineffectual Sympathetic Villain: Once Jenny has a chance to destroy Killgore with no one being the wiser, she decides she can't hurt a defenseless creature even if it's driving her crazy.
- Instant A.I.: Just Add Water!: Why a windup toy is sentient is not remotely addressed.
- Laughably Evil: He provides a lot of humor for wanting to be considered a threat while apparently oblivious of how most people find him adorable.
- My Little Panzer: As much as he claims otherwise, nothing about Killgore's design is dangerous—any danger he poses is instead a result of trickery and persistence.
- The Napoleon: If its 10 1/2 inch stature has any indication.
- Scare Chord: He keeps saying the classic "buh nah" chord.
- Saying Sound Effects Out Loud: SMACK!
- Third-Person Person: The mighty Killgore only refers to himself as "Killgore"!
- Tonka Tough: Somehow unable to be crushed by a closing-walls Death Trap.Jenny: Wow, that is one tough toy.
- Torment by Annoyance: SURRENDER!
- Villain Team-Up: With Armagedroid in "Enclosure of Doom", it worked...a bit too well.
- Villain with Good Publicity: Sure it may not be threatening, but what part of "Villian" don't the people who take a liking to it understand? All of it, apparently.
- Wind-Up Key: It's powered by a watch spring and a wind-up key.
A gigantic robot created by Dr. Wakeman back when she was a Skyway Patrol member for the purpose of eliminating alien weaponry. It turned its attention to human weapons in peacetime, forcing Dr. Wakeman to lure it into the Earth's core where it remained- for the time being.
- A.I. Is a Crapshoot: Its directive was to destroy weapons, and when it defeated an armada of hostile aliens, it turned its fangs on humanity, believing it must destroy their weapons, too, to bring peace.
- Badass Baritone: A quality that often comes with being voiced by Kevin Michael Richardson, of course.
- Cain and Abel: The Cain to the entire XJ series, being an earlier Wakeman protorype that has a vaguely similar color scheme.
- Destructive Saviour: Armagedroid, who was built for the purpose of eliminating dangerous weaponry, something that proved to be dangerous in peacetime.
- Evil Is Bigger: Way bigger than any adversary Jenny's encountered.
- Evil Sounds Deep: Courtesy of Kevin Michael Richardson.
- Killed Off for Real: Upon realizing he himself was a weapon, Armagedroid self-destructs. Given the series was discontinued and that Smytus survived a self-destruct, it's possible he may have returned at one point.
- Knight of Cerebus: Definitely not one of the more comical villains. He almost killed Jenny in their first battle!
- Knight Templar: It believes destroying all weapons will make the world safer, despite the fact he himself is a living weapon.
- Humongous Mecha: Taller than most of the buildings in Tremorton.
- Red Eyes, Take Warning: Huge red ones.
- Logic Bomb: Armagedroid's goal is to destroy all dangerous weaponry, so when Jenny points out that he himself is a dangerous weapon, he self-destructs.
- Villain Team-Up: Was later somehow rebuilt by Killgore. Unfortunately, it worked too well in Armagedroid's favor.
The Space Bikers
A gang of five fish-like aliens who come to Earth every so often to cause chaos. They are Letta, Sludge, Olga, Tammy, and Lenny.
- Abhorrent Admirer: Tammy is revealed to be attracted to Brad in "Ball and Chain" and even attempts to marry him. For the most part, Brad is very uncomfortable about Tammy's affections.
- All Bikers Are Hells Angels: They're first introduced as a gang of thugs who spend their lives partying and wreaking havoc in orderly places, but in "Voyage to the Planet of the Bikers", it's revealed they're only like that on weekends and live as schoolteachers on their homeworld.
- Bare Your Midriff: Olga and Sludge wear clothes that leave their midsections exposed.
- Biker Babe: With the exception of Lenny, they're all female bikers. Tammy stands out in particular.
- Butt-Monkey: Lenny tends to be regularly roughed up by Letta. And the bikers as a whole always suffer when they mess with Jenny.
- Fish People: Their species sorta resembles the Creature from the Black Lagoon.
- Green and Mean: They have green skin.
- Happiness in Slavery: Lenny is genuinely content being Letta's pet. He gives Brad a thumbs up when he suffers the same fate, and when his leash is cut the first thing he does is try to tie it back.
- Hartman Hips: Tammy has very large hips.
- Huge Girl, Tiny Guy: Lenny is minuscule compared to all of the other Bikers, especially his wife Letta
- Laser-Guided Karma: "Voyage to the Planet of the Bikers" have them finally supper a large comeuppance by losing their jobs and reputations as beloved teachers after being outed. They kind of deserve it for pranking Jenny by converting her into a motorcycle and soldering her joints so she can't return to her normal form along with their general behavior on earth.
- Non-Mammal Mammaries: Despite being fish people, Letta, Sludge, and Tammy have breasts. Seemingly averted for Olga, though she appears to wear a crop top.
- The Noseless: All of them except Tammy lack noses. Tammy turns out to have a nose when her full face is revealed in "Ball and Chain".
- The One Guy: Lenny is the only male in the group.
- Punch-Clock Villain: They only come to Earth to raise mayhem on weekends as a way for blowing stress off from their jobs. Outside of that, they're perfectly decent, hard-working people.
- Quirky Miniboss Squad: For Jenny. They're a group of villains who constantly show up to cause trouble in Tremorton, only for Jenny to beat them with ease most of the time.
- Reality Ensues: While it's understandable they may want an activity to release their pent-up stress after long weeks of being schoolteachers, but being crime-causing bikers is very much not okay and they end up fired when the they are exposed on their homeworld.
An evil mad scientist who is the father and creator of Melody.
- The Bad Guy Wins: Killing the heroes aside, Dr. Locus successfully accomplishes his objective in "Bradventure" by copying Jenny's abilities and installing them into Melody.
- Bald of Evil: He has no hair on his head.
- Beard of Evil: He has a scruffy white beard.
- Bitch in Sheep's Clothing: Initially presents himself as a kindly old man to Brad, but quickly drops the act once he realizes he can use him as bait to trap XJ-9.
- Bond Villain Stupidity: Averts this by refusing to tell Brad his evil plan, though later he forgets he didn't.
- Creepy Blue Eyes: One thing noticeable is that his eyes are blue instead of black like most other characters.
- Eaten Alive: Gets devoured by Dr. Wakeman's garbage disposal machine in "Turncoats".
- Evil Is Hammy: He enjoys gloating this way.
- Evil Counterpart: Like Nora Wakeman he's a Mad Scientist with a robot teenage daughter. Unlike Nora, he's doesn't treat his daughter with respect and is evil.
- Evil Old Folks: He's pretty old.
- Green-Eyed Monster: The reason he's angry with Nora is because his inventions were less popular.
- Knight of Cerebus: He ultimately succeeds in his debut episode and he came rather close to kill both Jenny and her mother in the show's final episode.
- Mad Scientist: He's an inventor with questionable sanity and morals, though he insists he isn't.
- Pragmatic Villainy: He refuses to tell Brad his evil plan. However later he seems to forget this and thinks he did, prompting him to try to kill Brad.
- Top-Heavy Guy: He has a large broad torso and legs that are basically nubs.
- Unknown Rival: Dr. Wakeman had no idea he existed until he showed up in the last episode.
- Achilles' Heel: Being comprised of electricity makes him extremely vulnerable to water, which shorts him out.
- Curb-Stomp Battle: Because he's living kryptonite for electronics, he easily defeats Jenny in "Mind Over Matter" multiple times, to the point she enlists help from her mother and friends to defeat him.
- Evil Is Bigger: His size increases as he absorbs more energy.
- Evil Is Hammy: His voice and personality are reminiscent of Dracula.
- Knight of Cerebus: He's quirky, but Gigawatt's very nature is to drain power, which is lethal to an electronic like Jenny. His powers make him a walking EMP capable of inducing blackouts to entire cities with his mere presence.
- Our Vampires Are Different: He's an energy vampire, in that he feeds on power rather than blood.
- Clingy Costume: Clingy skin. Upon gaining sentience, the skin wouldn't allow Jenny to simply remove it, even forcing itself back on in her sleep.
- Expy: It's a sentient suit that eventually grows a mind of its own and doesn't like being separated from its host. Now, are we talking about the skin or Marvel's Venom?
- Royal "We": It uses this when attached to a host.
Britt & Tiff
The antagonists of Jenny's life in high school, they seek to humiliate her at every turn.
- Alpha Bitch: They torment Jenny simply because a super-powered robot would otherwise be more popular than them.
- Attention Whore: There was a whole episode that revolved around these two setting Jenny up to be splashed in oil because Jenny was getting more attention than them in her new design.
- Ambiguously Brown: It's not stated what Brit's ethnic background is, though Indian makes the most sense, considering her English accent and Britain's past colonisation of India. She could also be South African for the same reason.
- Bare Your Midriff: Tiff's normal costume. Some of Brit's fashions in "Victim of Fashion" do it as well.
- Bifauxnen: As demonstrated in the picture above, Brit appears somewhat androgynous at times.
- British Teeth: Downplayed by Brit, who simply has slightly goofy-looking buck teeth. One Grossup Closeup implies they're much worse than they look from a distance, though more crooked than dirty.
- Bullying a Dragon: Jenny is sweet, gentle, and kind. She wants to fit in with her peers, and is a generally good person. Brit and Tiff, however, don't ever seem to grasp that she's also a walking, talking, sapient weapons system capable of destroying entire space fleets on her own. However, it's justified since If Jenny retaliates, she'll most likely get in more trouble than Brit and Tiff will. Unlike Jenny, Misty does not care and would torment and hurt Brit and Tiff.
- The Dividual: Syndividual; they look very different and have some contrasting personality traits, but are almost always together and acting in unison.
- Eerie Pale-Skinned Brunette: Tiff, which contrasts with her Pretty Fly for a White Guy-style speech.
- Even Evil Has Loved Ones: Brit and Tiff do seem to genuinely care about each other as cousins
- Fat and Skinny: Tiff and Brit, respectively. Tiff is more curvy than fat, but she still greatly contrasts Brit physically.
- The Fashionista: Both of them have impeccable dress sense, and are always seen wearing a new trendy outfit whenever they appear.
- Future Loser: In "The Price of Love" we see that in 20 years Brit and Tiff will become poor and ugly.
- Girly Girl with a Tomboy Streak: Downplayed with Brit. While she occasionally dresses in an androgynous style, she otherwise possesses the standard haughty queen bee personality, and frequently wears very feminine clothing.
- Hartman Hips: Tiff sports a pair.
- HeelFace Door-Slam: In their first appearance, Brit and Tiff actually defended Jenny when the police were planning on bringing her downtown after the science lab caught on fire (which they caused), as thanks for saving their lives. They actually wanted Jenny to start hanging out with them, until Brit shook Jenny's hand too hard and dislodged the hair pin Tiff shot into it. As the two were being led away by the police, they blamed Jenny for it.
- Hoist by His Own Petard: More than one of their schemes have terribly backfired.
- Lean and Mean: Brit is both tall and incredibly skinny. She is also generally portrayed as the leader of the two. In comparison, Tiff is noticeably short and curvy.
- Mean Brit: Brit has the accent and the attitude, though one wonders if she's actually British or not.
- Meaningful Name: Brit speaks with a British accent, and a "tiff" is a kind of petty squabble, which the two frequently instigate.
- Noodle People: Brit is very tall and skinny, which stands out opposite the short and curvy Tiff.
- Pretty Fly for a White Guy: Tiff is very pale-skinned, but speaks almost exclusively in slang. This is made even more noticeable when opposite Brit, who speaks with a refined British accent.
- Red Oni, Blue Oni: Brit is more soft-spoken, cold and manipulative while Tiff is more loud, brash and aggressive.
- The Quisling: Sided with the Cluster after they invaded Earth in "Escape from Cluster Prime", advising who and where to find people to enslave. Once it looks like the Cluster are losing, they switch back just as quickly.
- Spoiled Brats: They're filthy rich, attention-seeking, have the crowd wrapped around their fingers, picking on poor Jenny and overall getting their way....most of the time.
- Those Two Bad Guys: A pair of queen bees with a habit of tormenting Jenny Wakeman.
- Unlimited Wardrobe: They both wear new outfits in every episode they appear in. Sometimes, they wear multiple outfits in a single episode. No matter the case, they're never seen wearing the same thing twice.
The most popular boy in school. Jenny used to have a crush on him.
- The Casanova: Implied to have gone on brief dates with most girls in the school.
- Jerk Jock: A total hunk, but also a total douche.
- Jerkass: He regularly insults and belittles the unpopular kids and only saw Jenny as a girl to date on his list.
- Meaningful Name: His name is a play on "prima donna", which means a person with high expectations and an inflated ego who gets angry when their expectations are not met.
- What Does She See in Him?: Thankfully Jenny seems to have lost interest in him after she sees he cared more for his shoes than her.
- Wild Teen Party: He throws one in The Great Unwashed.
The best friend of Brit and Tiff who's often seen accompanying them.
- The Beard: As a part of Sheldon's Operation: Jealousy.
- Berserk Button: When people pronounce the "p" in her name.
- Beta Bitch: Seems to be next in the social status after Brit and Tiff
- A Day in the Limelight: She's usually just in the background or a Satellite Character to Brit and Tiff, but in "The Price of Love" she plays a major role as Sheldon's fake date.
- Evil Redhead: She's a cruel bully with red hair
- Future Loser: In 20 years she's shown to marry (and have a son with) Jerk Jock Sebastian, whom she needs to regularly bail out of jail.
- Greed: She extorts money from Sheldon after he offers to pay her to date him.
- My Nayme Is: "It's pronounced Teresa!". Only the Crust cousins seem to get it.
- Spoiled Brat: No better than her two friends, especially in "The Price of Love".
A citizen of Cluster Prime who seems wholly non-confrontational. Eventually revealed to be the princess of Cluster Prime.
- Action Girl: She proves to be a capable fighter after unlocking her powers.
- Blade Below the Shoulder: Once she installs her chip, she's able to access her weapons, including these.
- Mad Scientist's Beautiful Daughter: She's a robot from Cluster Prime, a race previously seen only as hostile. She's also Queen Vexus' daughter, and becomes the queen after Vexus' regime is overthrown.
- My Species Doth Protest Too Much: She's the first named Cluster character who reveals herself to be friendly. In fact, all the citizens are friendly, in contrast the tyrannical military.
- Nice Girl: Despite being Vexus' daughter, she's actually very friendly.
- Power Gives You Wings: Dragonfly wings, in her case.
- Royals Who Actually Do Something: When she learns her mother has been deceiving the planet, she's quick to inform the people and even assumes the role of queen after dethroning her mother.
- Similar Squad: Her circle of friends look just like Jenny's friends back on Earth, with Vega being the counterpart to Jenny herself.
An alien girl with superpowers who met Jenny as part of a team. The team later disbanded, and Misty returned to Earth.
- Bifauxnen: One of the more (tom)boyish-looking girls on the show.
- Cool Loser: Like the rest of Team Teen and Jenny, she is a misfit but she is pretty good at her job.
- Curtains Match The Windows: Purple hair and purple eyes.
- Destructive Saviour: She doesn't care about any collateral damage she causes as long as she gets paid or has fun. She tries to use a schoolbus full of children to crush a monster.
- Even Evil Has Loved Ones: Even when she becomes a selfish mercenary, Misty still considered Jenny her friend and was willing to help her out without expecting anything in return. When Jenny realizes how dangerous she is and they fight, Misty wins but can't bring herself to kill Jenny, claiming it was because no one was paying her for it.
- Evil Cannot Comprehend Good: She was absolutely confused by Jenny's remorse for scaring the Crust Cousins to tears.
- Evil Counterpart: She ultimately ends up as one to Jenny: they're both superheroes that consider themselves outcasts, but Jenny's friends and family motivate her to user her strength for good while Misty's detachment from almost everyone else leads her to abusing her power for personal gain and satisfaction.
- Evil Former Friend: She was pretty much Jenny's best female friend. But Misty got more ruthless to the point she only thought of helping people if she could benefit from it. All to the point where Misty nearly kills Jenny in a fight where Jenny was clearly outmatched (due to a couple of factors). The only thing that stopped Misty and snapped her somewhat back was Jenny still pleading that she still saw her as a friend.
- Expy: Since Team Teen is an homage to Teen Titans, she eerily resembles Raven.
- Human Aliens: She's an alien, but pretty much looks like a human.
- Only in It for the Money: By "Mist Opportunities", she attempts to charge money for her services and is callously unashamed in leaving people to their fate if there's no money in saving them. After giving a brutal beating to Jenny at the end of the episode, she even claims that the only reason she's sparing Jenny is because no one is paying her to finish her off.
- Parental Abandonment: Her and the rest of the Teen Team are apparently all orphans. She tries to justify charging for her services to Jenny by contemptuously pointing out she doesn't have any parents to provide for her.
- Perky Goth: She has a gothic appearance and has an upbeat, care-free demeanor.
- Punch-Clock Hero: In "Mist Opportunities", she's decided to help people on a pay-only basis, and left Tremorton to be destroyed by a monster when they wouldn't pay her for what she'd already done.
- Sudden Sequel Heel Syndrome: When Misty was part of Team Teen, she did superheroics without any expected reward, albeit seemingly because it was fun and with a condescending attitude toward "normies". After coming back to Earth and enrolling at Tremorton High, she shows she can be a rather vindictive bully. After she's expelled, then moves back to Tremorton, Misty is basically just a money-grubbing mercenary who'll endanger civilians to get her job done faster.
- Superpower Lottery: Let's see: she's a skilled martial artist, has Super Strength, can fly, turn into mist, shoot laser beams from her eyes, and control peoples' minds.
- Super Smoke: Her most often used superpower is her ability to turn into a cloud of purple mist at will (hence her name).
- Took a Level in Jerkass: In "Teenage Mutant Ninja Troubles" and "Mist Opportunities", she becomes more callous, self-centered, and materialistic.
- You Gotta Have Blue Hair: Misty has purple hair.
The gentle daughter of a Mad Scientist named Dr. Locust. She has a crush on Brad, but is secretly a highly advanced android.
- Big Damn Kiss: Gives this to Brad to ease him up about her being a robot. It works.
- Creepy Blue Eyes: To add to the creepiness, her pupils are blue while her iris is black.
- Good All Along: Jenny believes her to be evil due to being a creation of Dr. Locus. Turns out she ran away from her father and just wants to make friends and fit in as a teenager, like Jenny.
- Good Thing You Can Heal: She is less durable than Jenny but makes up for it by fixing herself instantly.
- Hair of Gold, Heart of Gold: She has blonde hair to match her sunny personality.
- I Just Want to Be Normal: States this during her fight with Jenny.
- Mad Scientist's Beautiful Daughter: As the daughter of the wicked Dr. Locust.
- Ridiculously Human Robot: Especially when compared to Jenny. She has skin and facial features that are indistinguishable from a human.
- The Presents Were Never from Santa: Brad appears to unassistedly carry Jenny (a 600-pound robot) and rescue her from Dr. Locus' lair. It's revealed that Melody was secretly helping him that time.
- The Rival: To Jenny.
- Robotic Reveal: Jenny forces this on her during her date with Brad. He doesn't seem to mind.
- Robot Girl: As revealed at the end of her first appearance, but Brad only learns about it in her next one.
Dr. Phineas Mogg
A scientist who is the rival of Nora Wakeman, and creator of YK-9 (AKA Kenny).
- Amazing Technicolor Population: He has green skin.
- Green and Mean: He's a jerk.
- Love-Obstructing Parents: Drags Kenny away from his date with Jenny, since he doesn't approve his son being in a relationship with his rival's creation. Although at this point, Jenny was only dating Kenny for popularity, not because she loved him.
- Mad Scientist: Like Nora.
- Pet the Dog: In "Agent 00' Sheldon" he genuinely seems concerned his son is missing.
- Punny Name: His name is likely a play on Phileas Fogg, the protagonist of Around the World in 80 Days.
- Shoddy Knockoff Product: Most of his inventions are copies of Nora's, including his son.
- Sitcom Arch-Nemesis: His relationship to Nora.
- You Gotta Have Blue Hair: His hair is also green.
Phineas Mogg's son who's a male knockoff of Jenny. They briefly dated, but she was no longer interested once she realized he was part-dog.
- Amicable Exes: Though they never broke up on screen, it's safe to say he's no longer in a relationship with Jenny. Despite this, the next time they meet they appear to be on good terms.
- Animal Jingoism: Immediately chases Sheldon once he dresses up as a cat.
- Dating What Daddy Hates: Continues to date Jenny even though both their parents disprove of it.
- My Instincts Are Showing: He displays dog like behavior, such as licking, barking, and chasing cats.
- Nice Guy: He's rather chill and treats Jenny kindly.
- Mundane Utility: He's able to use his robot body to cook pizzas. It gets him really popular with the other kids.
- Punny Name: The K-9 part of his name reveals his true nature.
- Robot Hair: It appears to be a normal haircut, but it can look like dog ears.
- Spear Counterpart: He was created to be a male version of Jenny. Who's also part-dog.
- Super Senses: Being part-dog he has enhanced hearing and smell.
Dr. Nora Wakeman's sister who is a flower child and focuses on the natural world and biological in contrast with her mechanical-based genius sister.
- Big Little Sister: Maybe. It's not known whether Wisteria is the older or younger one. However, she is definitely taller than Nora is and Wisteria retained her hair color while Nora's is white. On the other hand, in the family album, a teenage Wisteria is shown right after a picture of seeing Nora in the second grade.
- Granola Girl: One of the things that set her apart from her sister, Nora.
- Green Thumb: She did end up creating Glenn Wakeman, a swamp monster-like entity who can manipulate plants. She also snapped her finger to cause a plant to grow as she stepped off her wagon.
- Here We Go Again!: Despite having patched things up in their episode and gained an appreciation of family, they start bickering at the end of the episode, to the great annoyance of Jenny and Glenn.
- Maiden Aunt: Counts as this toward Jenny, even if Nora is also single. Granted, when Wisteria heard about Jenny, she did assume initially it was a normal human child.
- Not So Different: Despite their vastly different lifestyles and ideologies, they're both very stubborn in what they believe in, not to mention they're both single women who used their expertise in their fields to create a child in very unorthodox ways (Nora and robotics with Jenny and Wisteria and nature with Glenn.)
- Truly Single Parent: Much like her sister, she created her own child, who, much like Jenny, is not human.
A strange little swamp-monster like guy, he was created by Wisteria Wakeman and treated like her son. This makes him Nora's nephew and Jenny's cousin.
- Acrofatic: He's plump but can put up a fight if he chooses to.
- Black Bead Eyes: Has these instead of the regular pac-man eyes.
- Combat Tentacles: Uses vines as these.
- Green Thumb: During his (fake) fight with Jenny, he is able to shapeshift his various limbs and parts of himself into different plants like vines and cacti.
- Nice Guy: He is a very sweet and cheerful fellow and unlike their mothers, he gets along very well with Jenny.
- Plant Person: A big contrast with his metallic robot cousin, Jenny.
- Simpleton Voice: Speaks this way, likely to contrast with the high-tech Jenny.