Badass Crew: Even when not on Lyoko, Ulrich and Yumi possess advanced martial art skills, Odd is athletic and relatively good at adapting to situations, and Jérémie is able to help as much as the others without even fighting. It's saying something that they fought against XANA's attacks several times and still survived long enough for Aelita to disactivate the towers.
Teeth-Clenched Teamwork: At their beginning, they had limited loyalty to each others besides keeping the secret and would often argue or be missing (in Gravity, Ulrich flat-out refuses to help deal with the current attack so he can take part in a soccer match). They get better over the course of the series.
"Who's the dork that pushed me into Sissi's arms?"
Voiced by: Barbara Weber-Scaff
The unofficial hero of the show, and the main favorite of fangirls. He is a quiet and introverted person by nature, quite the opposite of his best friend, Odd. Headstrong and stubborn, he cares for his friends and would do anything for them. Ulrich is more athletic than academic and it shows when you compare his grades to his sports performance. He attracts the attention of many females of the school, but has obvious feelings for Yumi. He manifests in Lyoko as an unarmored samurai, with the ability to "Triplicate" into three of himself, and Super Speed. His katana can deflect XANA's creatures' energy attacks.
Abusive Parents: Ulrich's emotionally abusive dad; he seems to only care about his son for his grades, and, if Ulrich's talk is anything to go by, hasn't talked to him for a year. Not to mention his mother who acts as an enabler by sitting by and watching her husband berate their son.
Achilles' Heel: He has vertigo, which flares up at rather inconvenient times.
Big Man on Campus: Considered handsome by almost every girl in Kadic, and a skilled soccer player to boot. Notably, he is not exactly happy with it, as it causes him to have Sissi as a Stalker with a Crush.
Book Dumb: He is far from being actually dumb, but his grades are obviously bad. This is the major source of his tensed relationship with his father.
Bring It: Like Odd, he sometimes does the "bring it" Bruce Lee gesture.
Calling the Old Man Out: In the season 3 finale, his father comes to Kadic to talk to him about his bad grades. At first Ulrich silently submits himself to his criticisms; then his father suggests his friends are the cause of his grades, and Ulrich replies with this trope:
"Well Done, Son" Guy: A whole Ulrich-centered episode has him constantly seeking approval from his ultra-exigent father. He gets it in the end... at the apparent cost of his father's life. And then promptly has it Reset Button'd. Poor guy.
Doppelgänger Attack: "Triplicate" allow him to generate two duplicates of himself. In the first season they only act as decoys to distract enemies, but Season 2 has him using them as allies that can attack of their own.
"That's just the Magical Odd Effect. You see me once and you feel as though you've known me all your life!"
Voiced by: Matthew Géczy
The only extravert of the Team, and an incorrigible smart-aleck. He dresses in flashy, clashing colors, mostly purple and yellow. Though physically petite compared to the rest of the team, he is an adrenaline junkie, just the type to go for extreme sports. Also a passable student; his strengths are in the languages and artistic classes. He's a big flirt who's dated about every girl in his grade (most of them for only a day or two) as well as a few others. He has smuggled his small dog, "Kiwi", into the dormitories. In Lyoko, his avatar is a Cat Boy version of himself, including claws and a tail. He has heightened agility and stamina in this form, and can shoot "Lazer Arrows" from his forearms — which, for a time, tended to run out of ammo at the worst possible moments. This shortage was resolved in Season 2 at the expense of another of Odd's powers, the "Future Flash" which offered spontaneous visions of the mostly immutable immediate future. This left Odd with the short end of the stick powers-wise, a fact lampshaded in Season 3's "Triple Trouble" when Jérémie tries to give Odd a teleportation ability, but ended up making two clones for him instead, and the clones wind up not disappearing when no longer needed. At least he still has a marginally useful energy shield, granted as part of the Season 2 power realignment.
Anime Hair: A rare justified example: he is explicitly mentioned to use gel to keep his hair that way (though that doesn't explain the bi-color part). Notably, he originally had a regular hairstyle in the prequel, and changed it according to what he looks like on Lyoko (twice).
Crouching Moron, Hidden Badass: For all his silly jokes, Butt Monkey status and tendencies to go crazy in fight, Odd definitely is a skilled fighter. At several points, he has been able to deal with large amount of monsters entirely on his own, escape or distract Xanafied people on Earth and save Aelita. Not to mention he was the one who finally took down William, allowing the Lyoko Warriors to get him back.
Empowered Badass Normal: When Jérémie used a Tower to gives him powers for a short amount of time so he could fight toe-to-toe with a XANA-possessed Yolande.
KidAnova: He has had relationship with almost every girl in his school, Yumi, Aelita and Sissi excepted (and even then, he once replaced Ulrich as Yumi's partner at dance, flirted with Aelita upon first meeting her, and Sissi gets moments with him several times too).
Leeroy Jenkins: He rarely has any strategy before charging; most of his tactics consist either in doing something completely crazy or going ahead shooting at the enemy. Even his own teammates have some doubt about his sanity.
Aelita: You call this being careful? I call it being COMPLETELY NUTS! Odd: Isn't that the same thing?
Meaningful Name: Aside from the obviousness, "Odd" may also come from "Odr", meaning "tip of the arrow".
The Nicknamer: He's the one that names all the monsters (even complete with Xtreme Kool Letterz). As if that wasn't enough, two episodes reveal that he also calls some monsters by ordinary human names such as "Lucy-Ann". He's also responsible for Jérémie being called "Einstein" and Aelita "Princess" most of the time.
Outnumbered Sibling: Odd reveals in the episode "Distant Memory" that he has five older sisters who bully him.
What Kind of Lame Power Is Future Flash, Anyway?: Not only does this power have very limited scope (Odd is the only one unable to use his power at will, and it's worthless in a fight), but the power activating causes Odd to stop moving for a while, making him an easy target. Lampshaded when Odd mentions Jérémie erased it accidentally and never bothered reprogramming it because he felt it was useless. It's actually suggested that he is more effective without it.
"Black is my color. Black, like your eye will be if you don't back off!"
Voiced by: Mirabelle Kirkland
The tallest and oldest of the group. A good student, she is a Japanese national at the boarding school, living off-campus with her family. She is one grade above the rest of the Team, which proves sometimes problematic. While she may have feelings for Ulrich, Yumi is exasperated by his inability to articulate his crush. Her virtual form is a geisha with a collapsible razor-edged fan, with which she can deflect energy bolts. The fan is controlled telekinetically, and can be thrown as a ranged weapon, returning to her hand after an attack. Yumi also exhibits telekinetic power over several objects of the Lyoko landscape — most often boulders in the Mountain or Desert sectors. A running joke among fans is XANA's tendency to single her out for attack.
Designated Victim: Which can be explained by Yumi being the only one amongst the Lyoko Warriors to not be in pension, making her isolated and as such an easy target for XANA's attacks. One could argue her role as the group's Cool Big Sis and the fact she's the most reluctant to keep fighting might help as well, considering XANA's habits to play with people's minds.
Dude Magnet: For a girl supposely not as remarkable as Sissi, it's amazing how many guys want her. Apart from Ulrich, William, Théo Gauthier, Johnny...
"OK, XANA. What do you have in store for us this time?"
Voiced by: Corey Padnos (2001), Sharon Mann (2004-2007)
Jérémie is the computer genius whom operates the Supercomputer and allows the interface. He's also the leader of the Team, and shows good tactical skills even under pressure. As the most level-headed, he keeps the infighting within the group to a minimum. He can even get a bit authoritarian, despite being the youngest. Jérémie is one year younger than Ulrich and Odd, having skipped a grade. He has more than a crush on Aelita, and it's largely this motivation that keeps the Team going in time after time to shut XANA down. Though he has been virtualized twice, this has never been done on camera — something of a Lampshade Hanging on the second occasion.
The Dulcinea Effect: As soon as he meets Aelita and sympathizes with her, he becomes obsessed with finding a way to defeat XANA without having to sacrifice her, despite shutting down the Supercomputer with her still inside being the easier way out. Frequently lampshaded by the other Lyoko-Warriors.
The Insomniac: Frequently spends entire night working on programs to materialize Aelita or improve the Lyoko-Warriors' equipment. In one episode, Aelita finds out he didn't even realize the night was over.
Rapid-Fire Typing: Wild Mass Guessing presumes the keyboard on the Lyoko supercomputer has a second Return key in place of the capslock key. That or Jeremie types at a ridiculously high WPM. Or both.
Science Hero: He dislikes going on Lyoko, and it's suggested he is a poor fighter anyway. He makes up for it by being the Supercomputer operator and creating most of the upgrades the Lyoko-Warriors use.
"And just forget about my past, you think that's easy? You didn't spend ten years of your life as some sort of computer software!"
Voiced by: Sharon Mann
Aelita started out as the Damsel in Distress in the series. Unlike the other characters, she seemed to have originated on Lyoko, and survived there for years. The first season of the show deals with Jérémie and the Team trying to figure out a way to materialize her into the real world. She originally had two special abilities in Lyoko: she could enter the access towers that XANA uses to interface with the real world and shut them down, and she had the ability to morph the virtual landscape around her to create walls, rockslides, etc. Starting with Season 3, she was no longer in danger of being killed if losing all her Life Points. She gained the ability to attack with spheres of energy as well, and obtained wings in Season 4 with her new outfit.
Action Girl: Initially not, but she start developing traits of it in season 2 and fully becomes one starting with season 3.
Damsel in Distress: She plays this entirely straight in season 1 (no weapon other than Creativity, and dies if she loses all her life points), almost to the point of being a Damsel Scrappy. She gets a bit better in season 2, but still finds herself depending upon the other three most of the time. By season 3 she's upgraded to Action Girl status.
Designated Victim: Very justified, since she is the key to stop XANA from attacking Earth. As such, it's only natural for XANA to focus on her.
Older than She Looks: Aelita is chronologically 23-24, but ten of those years were spent asleep in Lyoko (and another full year in avatar form), so she looks, acts, and is 12-13. Finally confirmed in "Wrong Exposure".
Took a Level in Badass: In season 1, Aelita required Odd, Ulrich and Yumi as bodyguards, and her only use was deactivating towers. Out of all 26 episodes of season 1, she only destroys one monster. By season 4, she's the most capable Lyoko Warrior of all — not only does she have Energy Fields, which are more powerful than any other Lyoko weapon, she also has wings for flight. It's also worth noting that XANA-possessed Aelita has only ever been defeated once....
Undead Tax Exemption: Averted. The Lyoko Warriors have to do the work to create an identity for her (though Jérémie is very good at "arranging" her paperwork), and there are enough holes in it for Sissi to occasionally piece together that something's going on.
Distress Ball: Even after becoming an Action Girl, she always panics whenever the Scyphozoa is involved, and ends up getting possessed. This is particularly frustrating in "Wrong Exposure", where she forgets that she has wings, and thus could escape the Scyphozoa by flying away.
Romantic False Lead: To Yumi. In his first appearance, she seems to give back some of his feelings, but she gets annoyed by his Stalker with a Crush attitude as the show goes on. By season 3, it's made quite clear he never had any chance with her to begin with.
All Your Powers Combined: His Super Smoke power allows him to move as fast as Ulrich, fly like Aelita and can be used the same way as Yumi's telekinesis. Plus, he possess a hand-to-hand weapon that can shoot Razor Wind, and a buckler-like bracer to deflect and return attacks.
This malevolent A.I. is the main antagonist. Created by Franz Hopper to counter "Project Carthage", he rebelled against his creator and was sealed in the Supercomputer some 10 years before the start of the series. His true motivations are unknown, but he is hostile to humanity, and to the Lyoko Warriors in particular. He regularly attacks the real world through the Lyoko Towers. Being a program, he has no definite shape and manifests through the ever-present logo (or Eye of XANA) and the monsters on the Lyoko Sectors. He tries to escape the Supercomputer throughout Season 2 so that the heroes can no longer defeat him by cutting the juice, and after doing so he attempts to conquer the world in Season 4 by creating an army of robots.
Arch-Enemy: To the Lyoko Warriors and Franz Hopper.
The Bad Guy Wins: He partially succeeds in this in season 1 finale by preventing Aelita's escape from the Supercomputer. Seasons 2 and 3 end with him fully reaching his goals (respectively escaping the Supercomputer and destroying Lyoko).
Card-Carrying Villain: Judging by the song he used to hypnotize all of Kadic in "Killer Music" titled: "Glad When Your Bad".
Character Development: Ironically for a never-seen character, he gets lots of it throughout the series. His goals shift along with time according to the situation, his schemes become more complex, and his power increasing allow for varied and subtler tactics. As the series progress, he goes from something in the vein of a Generic Doomsday Villain in season 1 to a skilled Magnificent Bastard by the end of the show.
The Chessmaster: Not as much initially, but as the series progresses, he starts developing more complex schemes.
Dangerously Genre Savvy: He usually plans everything that can logically be planned, and, when he does make a mistake, he learns from it.
Enemy Mine: In "Marabounta" with the Lyoko Warriors.
Evil Computer Virus Cannot Comprehend Friendship: In season 1; due to his intelligence being based on pure logic, he was unable to understand why Jérémie would go into the scanners (something that is stated to terrify the young hacker) to save his friends. However, he is also notable for being one of the few villains to learn from it; in a later season 2 episode, he anticipates Aelita's Heroic Sacrifice and takes advantage on it to pull out a Batman Gambit.
Evil Plan: Downplayed. Other than "self-preservation" he doesn't seem to have an over-arching scheme. Though he does come up with more complex schemes as the serie goes on.
Instant A.I., Just Add Water: Justified, Franz made XANA and gave him the ability to evolve, before he learned that XANA was becoming too smart.
Manipulative Bastard: Though he has issues understanding emotions, he is still smart enough to develop various schemes based on emotional manipulation. As the serie progress, he gradually becomes better at it, eventually going near to the Magnificent Bastard level.
Hinted in "Marabounta"; after teaming up with the Lyoko Warriors against the common threat, they expect him to turn against them, but his monsters instead politely bow to them before retreating without any fight.
... but then has no problem betraying Jérémie in their second team-up the next episode.
Similarly, in "Ultimatum", when he attempts to blackmail the Lyoko Warriors into delivering Aelita to him by taking Odd and Yumi as hostages, he doesn't attempts to kill them until it's clear Jérémie refused, and even shows concern with keeping them alive.
Also when XANA possessed Jim and attacked Jérémie in "Final Mix", he merely restrained Jérémie when he quite easily could have killed him. Of course, this was before XANA grew to despise Jérémie.
Nothing Is Scarier: Seriously. The heroes are fighting an enemy trying his best to kill them who they never see, who almost never communicates with them. Still, he's obviously there, and it can clearly be terrifying at times.
Villainous Breakdown: Has one toward the end of Season 1, in the episode "Ghost Channel", where the above quote comes from.
The Voiceless: With the exception of the parts in "Ghost Channel" where he impersonnate Jérémie and "Franz Hopper" where he seemingly expresses himself through Hopper's clone, we never hear him talking. And even then, it's unclear if it was actually him talking.
XANAtos-Gambit: Any of his plans involving massive damages or witness can be considered as such: even if the Lyoko Warriors successfully stop his attack, they are forced to use the Return to the past to erase the event, making XANA stronger in the process.
Polite, efficient, deadly.
The dozen or so models of virtual monsters that XANA uses to defend activated towers and other important locations on Lyoko:
Guardians (Gardiens) — Not actually monsters, but force fields designed to trap a victim on Lyoko while XANA confused the heroes with tangentially-related real-world shenanigans. Used twice in Season 1 and shelved afterwards.
Roachstersnote Season one only, Kankrelats from season two on (Kankrelats) — As close to The Goomba as you'll get from XANA, these mollusk-like critters have a basic design: legs, a laser cannon housing, and little else. They often make up for their lack of individual strength with Zerg Rush tactics; their small size also allow them to hide and act as snipers. The first of two monsters to be fielded in the real world (in "False Start"). Quickly evolved into the Plucky Comic Relief among the monsters with their tendency for being Too Dumb to Live.
Hornets (Frelions) — The Airborne Mooks of Lyoko, looking like giant wasps with ten wings. They fly around, shoot lasers from their stingers, drip acid at close range (only in Season One), and make the Lyoko Warriors suffer for not having a dedicated anti-air weapon.
Bloks — Walking cubes about twice as tall as one of the heroes. The four side faces are marked with Eyes of XANA — one is the actual weak point, while the other three fire lasers, ice rays, and rings of fire respectively. The ice rays can paralyze the targets or devirtualize them if they're low on Life Points. The fire rings are the least often used, though both Ulrich and Odd got devirtualized by them in "The Secret".
Krabes — These four-legged, lanky six-eyed beasts deliver powerful laser attacks from both their eye arrays and underbellies. They sometimes also try to skewer the heroes with their pointy legs. Krabes are the first monster type to be deployed en masse ("The Chips Are Down", in which a line of several dozen guards the tower) and the second (and final) type to be deployed on Earth ("A Bad Turn").
Megatanks (Mégatanks) — A deathly powerful area denial weapon, these things consist of an arc-laser emitter cocooned within two indestructible shell halves which expand and contract to allow firing. Their attacks are arguably powerful enough to destroy Towers with enough concentrated fire (as attempted during Aelita's first transfer out of Lyoko in "Code: Earth"), but can be resisted with a couple of the Lyoko Warriors' weapons. They also move very fast by closing their shell and rolling on themselves, not hesitating to crush any unlucky hero in their path.
Tarantulas (Tarentules) — XANA's apparent first attempt at min-maxing its monsters: they have more Life Points than any other monster barring the Scyphozoa (as of its Season 2 rollout), the Eye of XANA weak point is small and located at the back of the head, and their mobility is largely sacrificed for high-speed firing of the laser cannon stubs on their arms.
Scyphozoa (la Méduse) — XANA's first Dragon, looking like a levitating giant jellyfish. It eschews direct attacking for wrapping its tentacles around Aelita and attempting to crack her Neuro-Vault open. Other notable targets include Yumi (to force a variant Friend or Idol Decision by making Aelita transfer her own materialization code to replace Yumi's deleted version), William (to make him the new Dragon), and the Skidbladnir (to sabotage its shield regeneration). It normally retreated when it was rendered unable to gain what it came for, only having been destroyed once in "The Lake" when it was overloaded, but XANA just made another.
Creepers (Rampants) — Worm-like monstrosities that inhabit Sector 5 exclusively, where they Wall Crawl at will. The unique laser cannon in their mouth is more powerful on average than those of other monsters. Notable for being one of the few enemies that explodes in a large quantity of Ludicrous Gibs.
Mantas — White-and-blue manta rays that "swim" through the air and shriek like hawks. As if XANA didn't have enough air superiority, these Giant Flyers hatch from the Celestial Dome surrounding Sector 5 and can deploy practically everywhere to shoot the regular lasers or poop deadly multi-terrain mines. William gains a black one as steed when under XANA's servitude.
Sharks (Rekins) — Shark-like monsters also native to the Digital Sea. Fire torpedoes instead of lasers.
Kalamar — Only seen once in the Digital Sea, it attempted to drill through the Skid's hull.
Kolossus (le Kolosse) — XANA's last-minute Giant Mook, appearing as a towering LavaGolem with a blade for a left arm. It foregos standard lasers to crush the Lyoko Warriors and the Skidbladnir with sheer physical power. It is harder to kill than most monsters, having two Eyes of XANA that must be hit simultaneously to destroy it.
Video-game monsters — The Volcano Replika and other locales in the Code Lyoko video games give XANA several extra additions to its bestiary, from lanky Insekts to hardy Volcanoids to the first DS game's Final Exam BossScorpion.
Artificial Stupidity: The monsters occasionally commit ridiculous mistakes, sometimes even shooting each other. This is lampshaded in "Marabounta", where Odd, while giving instructions to some of the Blocks XANA sent to help them against the Marabounta, mentions that "the only thing stupider than one Blok is two Bloks".
Attack Its Weak Point: No matter how much life points they have, it is possible to kill them instantly if you manage to hit the part of their body marked with the Eye of XANA. The only known exceptions to this rule are the Kolossus (who you need to hit on both of his two marks) and the Scyphozoa.
Imperial Stormtrooper Marksmanship Academy: They do gets some shot to the heroes, and even sometimes succeeds in devirtualizing them, but most of the time, they miss their target, especially when said target is Aelita.
The Speechless: They do not seem to have human intelligence, and do not speak beside shrieking, roaring or other unintelligible sounds.
Super Drowning Skills: With the exception of the Kongres, the Sharks and the Kalamar. Justified though, since this is Lyoko, where falling in the Digita Sea equals being disintegrated for them. Landbound monsters even sink in ordinary bodies of water, that you can find on the Ice Sector.
We Have Reserves: XANA can create as much of them as he wants, so he has no qualm about sacrificing them if necessary.
Polymorphic ClonesAn advanced form of XANA's Specters, the Polymorphic Clones have no need for a host and can take a human shape by themselves. They can copy many appearances, most often of the Lyoko Warriors or some adult to sow division or attack by surprise. They have the same powers as a XANAfied human with the addition of shapeshifting. They solely appeared on Earth, with the exception of one going to Lyoko through a scanner by replacing Odd in the episode "Revelation". Jérémie mastered the technology in Season 4 to create a short-lived clone of himself, and then a replacement for William. Both of Jérémie's clones, however, have a strange programming flaw: their personalities are partially inverted compared to the originals. The Jérémie Clone is an insufferable Odd-like KidAnova, while the William Clone is dumb as a sack of bricks.
Characterization Marches On: The prototype Clone in season 1 couldn't shapeshift and was rather terrible at impersonating Yumi, blowing its cover rather quickly. By season 2, XANA seems to have perfected them, and they are more than capable to fool not only the civilians, but also sometimes the Lyoko-Warrios themselves.
Foreshadowing: The Polymorphic Clones technically didn't appear until season 2, but season 1 had an episode where XANA did try something of a prototype by sending a Specter assuming the appearance of Yumi on Earth while the real Yumi was kept inside a Guardian.
Adults Are Useless: Usually played straight, but adverted with Jim, who occasionally helps a lot (the season 1 finale being the best example), and Franz Hopper, whose position as the Big Good ensure him being useful.
Daughter of Kadic Academy principal Jean-Pierre Delmas. She can have practically any boy at school — but she wants Ulrich, who'd rather have nothing to do with her despite (or maybe because) they'd known each other since childhood. To separate Ulrich from Yumi (not that they're actually together, honest), Sissi makes a variety of attempts to undermine the bonds of friendship between the Lyoko Warriors. These often manifest as attempts to administratively separate them through her power as a one-girl Absurdly Powerful Student Council or the use of blackmail material to buy her way into the group. Either way, she has the potential to sow a greater division than XANA himself. The prequel two-parter "XANA Awakens" reveals that she had initially been in on the Lyoko Warriors' secret, but her memories of the Supercomputer's activation were wiped with a RTTP because she notified her father due to thinking her friends were in danger and a misunderstanding of betrayal occured. Hints dropped from late Season 2 and through Season 4 seem to reinforce Fanon that Sissi could be perfectly content with Odd — so long as she doesn't realize it's a Bohemian like him that she connects with.
Demoted to Extra: In Season 3 and 4, especially 3 (she becomes relevant again late into Season 4).
Depending on the Writer: The level of sympathy her character is treated with changes from episode to episode; shown moreso in Seasons 2 and 4 (where she was sympathetic in the majority of her appearances) than 1 and 3 (where she... wasn't, though she did have moments in 1.)
Informed Attribute: Stated by Ulrich to be a Dude Magnet in the prequel; however, the number of boys seen actually hitting on her onscreen doesn't exceed three (Two of them being Odd and Hervé, and the third being a one-shot character who forgot about her as soon as he saw Yumi), and minor characters have been shown to be pretty aware of her being a Brainless Beauty. In fact, Yumi technically got more attention from boys than she did.
Throw the Dog a Bone: On occasion, and in the final episode, when the gang at last decides to make her an "official" friend. Also counts as Earn Your Happy Ending, as it feels like an ultimate reward for all the multiple times she's helped out but doesn't remember.
Unknown Rival: Yumi is mature enough to realize that Sissi is a Hopeless Suitor, and thus a rivalry between them is barely acknowledged on her part.
Unlucky Childhood Friend: She knows Ulrich and has a crush on him since Nursery School. Though the "friend" part remains unconfirmed, seeing how Ulrich didn't seem in good terms with her in the prequel.
Catch Phrase: "I'd rather not talk about it", when referring to the various jobs he had.
Crouching Moron, Hidden Badass: Most of time, he is portrayed as goofy, clumsy and a bit stupid, to the point even the students don't take him seriously. When given the chance, however, he can actually be competent.
Properly Paranoid: He is firmly convinced the Lyoko-Warriors are doing something behind everyone's back, an impression Delmas only sees as paranoia.
Sixth Ranger: Temporarily, at the end of Season 1. But then he gets his memory erased when the gang go back in time.
Why Do You Keep Changing Jobs?: Sure, Jim has a stable job now, but he's had 21 different ones in the past, from from sewer worker to basketball star to safecracker—ahem—locksmith to professional ping-pong player. All but a few of which he'd rather not talk about, and all in addition to 20 years at Kadic.
Yumi's younger brother, appearing in Season 2 and joining the 6th grade at Kadic at the start of Season 3. He shows some hero-worship toward Ulrich, and constantly hounds his sister to date the Stern boy and admit her feelings for him. A bit of a crook, he often blackmails Yumi into doing his homework in exchange for not tattling to their parents when she's out saving the world. Unwittingly tagging along in some of XANA's attacks, he tends to be a dangerous distraction (in "A Bad Turn"), but also shows some useful skills (like picking locks in "Hot Shower"). He never keeps memories of this thanks to the Returns to the Past.
Annoying Younger Sibling: His sole role seems to be teasing Yumi about her relationship with Ulrich. To say she finds this annoying would be an understatement.
Everyone Knows Morse: He does have an excuse for this, though; he and Yumi learned it to talk in secret at the table.
Remember the New Guy: Hiroki is nowhere to be seen in season 1, even though we see the Ishiyama household a few times. Even in "Holiday in the Fog", when the family are going on vacation, Hiroki isn't seen in the car. Yet when he shows up in season 2, no-one draws attention to his sudden appearance.
Shipper on Deck: Of his sister and Ulrich, though it's mostly about teasing her.
"Project Carthage was military program used to block enemy communication. [...] So I built the Supercomputer, created Lyoko, and last of all XANA, to destroy Carthage."
Voiced by: Paul Bandey (second season), Alan Wenger (third and fourth seasons)
Aelita's father, and the creator of the Supercomputer, Lyoko and XANA. His real name is Waldo Schaeffer. Also a former Science teacher at Kadic Academy.
Badass: He rarely manifest in person, but when he does, it almost always result in him doing something awesome to help the Lyoko Warriors. XANA considered him enough of a threat to miss a chance to destroy the Supercomputer and Lyoko Warriors for good if that meant not being able to deal with him.
Transhuman Aliens: Hopper is permanently virtualized into Lyoko, and his avatar is a brilliant ball of light, rather than a humanoid like the other Lyoko Warriors.
Mad Scientist: He built the Supercomputer, Lyoko and XANA on his own.
Virtual Ghost: Franz never bothered taking a corporeal form on Lyoko.
The Voiceless: While his voice is heard on screen, it's always either in a flashback, a recording, or a XANA trick. Hopper himself (in light ball form) is never heard to speak.
Clone William. Awwwwwww!
"To be specific, I'm a digitally-generated random polymorphic energy field controlled by a basic non-evolving behavioral program."
Voiced by: David Gasman
A Polymorphic Clone created by Jérémie to replace William throughout season 4 while the latter is controled by XANA, so that nobody at Kadic gets suspicious from his prolonged absence. The clone is close enough from the original to fool most people, although his programmation isn't quite perfect, making him a Literal-MindedDitz — and a big source of humor. Milly and Tamiya discovers something is amiss in episode "A Lack of Goodwill", and William's Parents quickly find out he's an imposter (in episode "Down to Earth"), just before William's return.
Odd's dog, which he brought secretly in Kadic and now hides inside his room with the help of Ulrich, since pets are forbidden at school. Kiwi tends to not do much besides eating, sleeping and in some occasion wreaking havoc in the room. Odd, however, is devoted to it.
Loophole Abuse: Used in one episode, where Jim finds out about Kiwi. When pointed out that pets are forbidden inside school, Odd notices that they are in the bus at this point, meaning they are technically outside school.
Open Secret: Pretty much every student at the school knows that Odd is keeping him in his room in defiance of the rules; Sissy even threatened to tell on him in one episode, but apparently changed her mind later.