Voiced by: Yuri LowenthalPower set: Super-strength and durability, heat vision, freezing breath. Can fly even without his Legionnaire ring... but not very well.
- Badass Cape: Would he really be Superman without the iconic red cape?
- Clark Kenting: Trope Namer. For this version of the story, both Superman and Clark are the "real person" wearing different clothes, neither being a disguise. The issue of a disguise persona is never dealt with in the show, which is justified because in the 31st century, people are only familiar to Superman as a legendary hero and there is no one to recognize him as Clark.
- Chest Insignia: Wouldn't be Superman without the S on his chest.
- Disney Death: Gets one in the season two finale "Dark Victory" when he supposedly dies after exposure to a Kryptonite crown, but later recovers after it turns out that he was merely put in a death-like state to recover from the Kryptonite poisoning.
- Extremity Extremist: Whenever he fights, Superman almost exclusively uses his fists.
- Fish out of Water: Both as a Kryptonian and as someone from the past.
- Flying Brick: He can fly and is very formidable.
- He's All Grown Up: In season two, WOW.Superman: "Who you calling skinny?"
- Innocent Blue Eyes: Of the "heroic and idealistic" variety.
- The Leader: He is not officially leader but the Legion defer to his judgment, if only out of respect to his heroic legacy.
- Naïve Newcomer: When he's first introduced but he gets to grips with it pretty quickly.
- Nice Guy: Hands down the nicest character in the show. He even attempts to convince Superman X about the values of friendship and teamwork.
- Out of Focus: In the second season, more attention is given to his successor Superman X. As a result, he appears much less frequently.
- Primary-Color Champion: Naturally. His costume has red, blue, and yellow and he's a very powerful hero.
- Red Oni, Blue Oni: The Blue to Superman X's Red.
- Rookie Red Ranger: He is recruited by the Legion to help them take down the Fatal Five when they overpowered them.
- Superpower Lottery: He wouldn't be Superman without this trope.
Voiced by: Andy MilderPower set: Here's a hint: he's not named Non-Electrocuting Lad.
- Artificial Arm: From "Chained Lightning" onwards, he gets a robotic arm after his original one got blasted off by Imperiex.
- Badass Beard: In season two, he has a beard.
- Butt-Monkey: He really hates Legion try-outs, usually because he winds up on the receiving end of someone's demonstration.
- In the spin-off comic of the cartoon, during Infectious Lass's try-out, he wound up with a form of lava acne and got stuck with Bouncing Boy's power (and physique). What sucked worse is that, the virus that switched his power with BB's lasts longer on people with greater mass.
- Cain and Abel: The Abel to Mekt's Cain.
- Cynicism Catalyst: The death of his sister Ayla during the attack that granted him and his older brother Mekt their powers pushes them into their guilt-ridden Cain and Abel complex, along with Garth's cynical attitude and Mekt's path into villainy. Subverted in that she didn't die at all and was eventually restored to a physical form.
- Fiery Redhead: He has red hair and is often short-tempered.
- Good Parents: He was seen embracing them after the storm that devastated Winath, happily embracing their children in the photo before he and his siblings got their abilities and him bringing Ayla home to see their parents.
- Good Scars, Evil Scars: Lightning Lad has a lightning bolt-shaped scar over one of his eyes.
- He's All Grown Up: Has a shirtless scene in Chained Lightning to demonstrate this. Much to the joy of Legion fangirls everywhere.
- Jerk with a Heart of Gold: He's arrogant and raucous, but he still fights for what is right.
- The Lancer: Becomes the second-in-command when Superman joins the team.
- Locked into Strangeness: His scar and eyes are a result of the Lightning Beasts shocking him and his siblings that granted them their abilities.
- Major Injury Under Reaction: When he comes to and realizes his arm has been replaced with a prosthetic, his response is to say "Sweet" in an impressed tone of voice. Somewhat justified due to being informed that his new arm is equipped with powerful weaponry.
- Real Men Wear Pink: Has surprisingly good bedside manner, as demonstrated by him trying to get Matter-Eater Lad to eat so he would recover quickly in the hospital. And then of course there's the fact that he loves his little, formerly twin sister dearly.
- Shock and Awe: His power is firing bolts of electricity.
- Teeth-Clenched Teamwork: With Dream Girl in season two. His reason for doing so is that she used to be a con artist fortune teller called Madame Mysterious, but the real reason behind his dislike is she told his parents that they would find his sister Ayla on another planet and it never happened, which devastated the two. Though their relationship has softened by the end of Nura's spotlight episode.
- Took a Level in Kindness: While still a bit of a jerk in season two, he'd softened a little. Not majorly, but considerably.
- Action Girl: She gets to join in the action frequently as one of the team's core members.
- Big Ol' Eyebrows: Her eyebrows are very prominent.
- Humanoid Alien: Clearly not quite human, but very similar.
- The Heart: She's quite good at handling people. She did show a great deal of compassion for Timber Wolf before his true identity was revealed.
- Master of Illusion: She can use her telepathic abilities to trick people into seeing things that aren't really there.
- Mind-Control Eyes: Her eyes glow whenever she uses her psychic abilities.
- Mind over Manners: Lightning Lad once stated that she could read a persons thoughts even when she's unconscious. Since she's unconscious she can't stop herself, and will sometimes pick up on things she shouldn't.
- Psychic Powers: Her main power is telepathy.
- Purple Eyes
- Rapunzel Hair: Her hair is long.
- Technicolor Eyes: She has violet eyes.
- Telepathic Spacegirl: She is an alien and she has mental powers.
Voiced by: Adam WyliePower set: Super-intelligence along with extensible limbs, reprogramming computers by touch, limited shape-shifting, and the Required Secondary Powers of a synthetic being.
- Adorably Precocious Child: An adolescent who acts more mature than his teammates.
- Ambiguously Gay: His devotion to Superman sometimes comes off as more than just mere admiration.
- Brainwashed and Crazy: When Brainiac 1.0 takes control of him.
- Do-Anything Robot: He has a robotic body and he can transform his arms into any tool or weapon needed.
- Green Skinned Space Guy: He's not exactly Mr. Fanservice, but that hasn't stopped his horde of fangirls.
- Genius Bruiser The genius part is blatantly obvious, the bruiser part comes in when he takes on a twelve-foot 'battle form'.
- I Did What I Had to Do: Less of a single occurrence and more of a defining motivational trait - Brainiac 5 often makes the tough, pragmatic and/or rational decisions, and willing to pay high costs (including sacrificing himself, or on rare occasions others) if he feels it needs to be done or the alternative is something much worse. This extends to everything from saving the day to preserving the timeline, and becomes particularly obvious in "Message In A Bottle" and other episodes dealing with Brainy ensuring that Superman doesn't learn too much about his past.
- Pointed out by the original Brainiac, who uses this part of Brainiac 5 to create a connection between himself and Brainy. As his resistance breaks down, Brainy slowly starts to believe that his tendency for this makes him Not So Different than Brainiac 1... and that's all 1.0 needed.
- In-Series Nickname: His teammates frequently address him as "Brainy".
- Insufferable Genius: He comes off as this to the rest of the Legion at times when his Techno Babble becomes tiresome
- Legacy Character: He is a descendant of the original Brainiac, one of Superman's enemies.
- Locked into Strangeness: In an interesting reversal he was an android at the start of the series but at the end he became human (albeit with green skin and white circles on his forehead) after defeating Brainiac in his mind.
- Losing Your Head: For most of the episode "Brain Drain", a teleportation mishap results in his head being separated from his body.
- Mechanical Lifeform: He is an android, but also acts human.
- Out-of-Character Moment: His entire character after the first few minutes of "Brain Drain" due to a malfunction. Hilarity Ensues.
- Pinocchio Syndrome: Per Word of God.
- Pragmatic Hero: "Phantoms" reveals he has a piece of kryptonite around, which would be sensible in case Superman went rogue. He also justifies erasing Superman's memory at the end of "Message in a Bottle" because he doesn't want to risk history being changed by Superman's knowledge of the future.
- Purple Eyes: His eyes are purple.
- Robot Buddy: He is an android and gets along well with the other Legionnaires.
- The Smart Guy: He is the brains of the team.
- The Spock: Focuses on logic to the point that he stubbornly tries to deny the existence of magic even while Zyx uses his reality-altering powers on him.
- Spock Speak: Part of his intellectual personality is using technical terms while speaking in a serious tone of voice.
- Telescoping Robot: He can extend his neck and limbs.
- Well-Intentioned Extremist: Comes off as this when he is controlled by Brainiac 1.0 in "Dark Victory", claiming that with his order he can end suffering and prevent everything from falling into chaos.
Voiced by: Michael CornacchiaPower set: Self-inflation and bouncing ability. Don't laugh too hard: he's exceptionally durable and an excellent tactician.
- Acrofatic: He's quite versatile for someone of his girth.
- Big Eater: The first episode alone makes it clear that he loves food. For instance, he's quite thrilled to discover hot dogs and cotton candy.
- Big Fun: He's overweight and all about having a good time.
- The Big Guy: He quite often uses his bouncing ability to break through barriers and pummel his enemies.
- The Chains of Commanding: Feels them when he gets put in charge of the Legion.
- Dark Horse Victory: Wins the Legion Leader Election in "Chain Lightning" despite Cosmic Boy and Lightning Lad being the frontrunners due to leading the Legion in saving all of Winath.
- Genre Savvy: Comes with being an ancient horror movie fanboy.
- Plucky Comic Relief: He serves as the jokester of the group.
- Hyper-Destructive Bouncing Ball: He IS one!
- Mission Control: When he is piloting and the others are in action. Exceptional work at this briefly gets him elected leader of the entire Legion.
- Ship Tease: With Triplicate Girl.
- What Kind of Lame Power Is Heart, Anyway?: He was rejected from the Legion four times before finally being let in.
- Heart Is an Awesome Power: He was let in eventually and is a useful member of the team by the time of the show.
Voiced by: Heather Hogan WatsonPower set: Well-controlled insubstantiality: the ability to induce insubstantiality in other people or matter.
- Action Girl: One of the team's core members, she's often involved in the action.
- Deadpan Snarker
- Eerie Pale-Skinned Brunette: She's much paler than the other girls in the show, and the design of her costume and face suggest a skull.
- Gray Eyes: Just like her mother's.
- The Heart: Served this to Lightning Lad and Timber Wolf when both were dangerously close to becoming murderers.
- Intangible Girl: Her power is phasing through solid objects.
- Little Miss Snarker
- Out of Focus: Receive less screentime in season 2 because of Executive Meddling.
- Screw the Rules, I'm Doing What's Right!: When she aids Timber Wolf despite the Legion's laws.
- Ship Tease: With Timber Wolf
- Spoiled Sweet: Her mom's President of the galaxy, in case you didn't know.
- This Looks Like a Job for Aquaman: She's the most powerful Legionnaire in the Phantom zone.
Voiced by: Shawn HarrisonPower set: Strength, speed, and durability. Becomes considerably more dangerous, in every sense, when enraged.
- Brainwashed and Crazy: Daddy dearest used his nanites to turn him into this, it was seeing Phantom Girl's unconscious body that snapped him out of it
- Calling the Old Man Out: Gives his pop a few of these
- Clear My Name: Was accused of killing his father and the Legion and Science Police hunt him down, as it turns out he was the real killer but the victim was his father's clone
- Dangerous Forbidden Technique: Timberwolf regards his alternate form as extremely hazardous, partly because he has no control over shifting back.
- Deadpan Snarker
- Guinea Pig Family: See Abusive Parents
- Guttural Growler: Especially when he's in his bestial form.
- Hidden Depths: He likes to cook.
- Lightning Bruiser: In S2 he's built like a tank, and although he's not as fast as speedsters or Superman, he still moves in a blur.
- Locked into Strangeness: In pictures it was shown he was a normal human boy until his father tampered with his DNA too much. After he was restored from his werewolf-like state he maintained the cat-like eyes, fur, claws, fangs and pointy ears from his feral form.
- Misunderstood Loner with a Heart of Gold: Was originally treated like a mindless animal (his father tricking the Legion so they can capture him) until Saturn Girl uncovered the truth
- Our Werewolves Are Different: He became a wolf-like humanoid because his father experimented on him.
- Resist the Beast: In "Cry Wolf" he does experience this trope and trying hard not to revert into his bestial form in one such instance he was struggling with his monster form when Phantom Girl tries to coax him back to normal...until the Science Police came in and attacked him causing him to run and fly to Rawl so that he wouldn't be a danger to anyone else.
- Ship Tease: With Phantom Girl.
- Skunk Stripe: Like his father, he has a white streak in his hair.
- Slasher Smile: Does this in Cry Wolf where the nanites have taken control over him
- Sixth Ranger: Joins the team by the end of his first appearance.
- The Stoic: Often has a serious demeanor.
- Supernatural Gold Eyes: The lupine sort.
- Vomit Discretion Shot: In the spin-off comic of the cartoon Timber Wolf gets motion sickness on the trip back from Rawl, fortunately Superman manages to get him off the ship before he could show the Legion what he had for lunch.
- Wolf Man: He's a humanoid wolf.
- You Wouldn't Like Me When I'm Angry: When angered, he becomes larger, more monstrous, and more aggressive.
Triplicate Girl/Duo Damsel
- Action Girl: She often appears on the scene to lend a hand during the team's battles.
- Bare Your Midriff: She wears this for the first series then only partially for the second series.
- Despair Event Horizon: When one of the duplicates is seemingly killed.
- Genki Girl: The most peppy and excitable of the female Legion members.
- Literal Split Personality: Each of the three duplicates she splits into are semi-individuals with slight differences in personality to the point that they're both one person and yet also like very close sisters.
- Magic Skirt: In spite of how short her skirt is, it never changes position.
- Me's a Crowd: When under the influence of magic, her duplication power spirals out of control creating dozen of copies that continue to endlessly fill the Legion's spacecraft.
- Peek-a-Bangs: Part of her hair covers one of her eyes.
- Status Quo Is God: After being minus a third of her for most of the second season, the series' end has her reunited with her restored third self.
- You Gotta Have Blue Hair: Her individual triplicate selves have white, orange, and purple hair. When she's whole, her hair has all three colors.
- Zettai Ryouiki: In keeping with her Genki Girl personality, wears Rank A as part of her uniform.
Voiced by: Alexander PolinskyPower set: Shape-shifting.
- Adorkable: Very charming because of how young and naive he is.
- Deadpan Snarker: Most notably in regards to Karate Kid's optimism.
- Hero-Worshipper: In 'Who Am I' it was shown he's idolised Superman for years before he even joined the Legion.
- In-Series Nickname: He is often addressed as Cham.
- Keet: He is very energetic.
- Kid-Appeal Character: He's mainly introduced in the second season because the other Legionnaires have become serious and more mature after the Time Skip.
- Magic Pants: His clothes disappear whenever he shapeshifts, but he somehow still has his clothes whenever he returns to his normal form.
- Memory Gambit: Was a part of this for Brainiac 5's plan of infiltrating Imperiex's forces by impersonating Persuader in "Who Am I?". In addition to assuming Persuader's form, Chameleon Boy had his mind altered so that he believed he really was Persuader. By the end of the episode, he's returned to normal and has his real memories restored.
- Plucky Comic Relief: Good-natured and fond of puns.
- Voluntary Shapeshifting: His power is changing himself into any living thing.
Voiced by: Yuri LowenthalPower set: Super-strength, invulnerability, heat vision, cold breath, flight.
- Anti-Hero Substitute: He's more antisocial than the original Superman and doesn't have any qualms with using excessive force.
- Adorkable: His upbringing changed a lot but he retains a lot of Superman's personality traits and has just as awkward as a time fitting in with society.
- Cloning Blues: He is cloned from Superman's DNA and is frustrated that the Legion find the original Superman superior to him.
- Composite Character: Of Kon-El (clone of Superman) and Superman from the 853rd century (A successor of the Man of Steel from even further in the future). Having Superman's powers but an immunity to Kryptonite also makes him similar to Mon-El/Lar Gand.
- Genetic Engineering Is the New Nuke: Created specifically to turn the tide against Imperiex in the 41st Century, he's the result of Superman's DNA being mixed with Kryptonite and as such is immune to the green rocks effects. It also has the added side effect of granting him different powers.
- Good Is Not Nice: His less than friendly demeanor has even led to the original Superman implicitly comparing him to Batman.
- Green Eyes: His eyes are green, presumably because of his DNA being combined with Kryptonite.
- Laser-Guided Tykebomb: He was created to stop Imperiex.
- The Only One Allowed to Defeat You: He doesn't want anyone else to defeat Imperiex.
- One Hero, Hold the Weaksauce: Kryptonite is mixed into his DNA; as a result, he's immune to it.
- Red Oni, Blue Oni: The Red to Superman's Blue.
Voiced by: Wil WheatonPower set: Metal control.
- The Captain: He is the de facto leader of the Legion of Super Heroes.
- Extra Oredinary: He can manipulate metal.
- Good Is Not Nice: While he's the leader of the Legion of Super Heroes, he's kind of a dick.
- Jerkass: He is very rude towards the inexperienced Chameleon Boy and also turns away Karate Kid just for lacking powers.
- Unresolved Sexual Tension: With Saturn Girl. In "Chain of Command", he tried to protect her from harm's way, but she told him he can take care of herself and leaves before he can apologize. In the episode "In the Beginning", he's upset with Saturn Girl for always taking Lightning Lad's side.
- What the Hell, Hero?: Lightning Lad calls him out for not even having the time to visit Saturn Girl while she's in a temporary coma.
- Annoying Laugh: She's a snorter
- Flower in Her Hair: A green flower is visible on her hair.
- Genius Bruiser: This type tends to be. That she is able to keep Braniac 5 in check is probably why her teammates tolerate the other tropes listed here.
- Ship Tease: She seems to spend a lot of time with Braniac 5.
- Shrinking Violet: Averted in spite of her name, visually she gets smaller and wears dark purple but she does not have this personality at all.
- The Napoleon: She's very sensitive about her height.
- What Kind of Lame Power Is Heart, Anyway?: Though she thinks shrinking is the best power.
- Raven Hair, Ivory Skin: Unlike the comic version
The Fatal Five
- Five-Bad Band
Lightning Speed Vanguard/Legion of Supervillains
- Fun with Acronyms: Although the initials don't spell out a word, they're the same in the old and later name of the team: LSV.
- Heel–Face Turn: Although they weren't seen after their "turns", Lightning Lord and Ron-Karr.
- Jerk Jock: Mekt "Lightning Lord" Ranzz in "Champions", before joining the LSV.
- Jumping Off the Slippery Slope: The Light Speed Vanguard at first seem Cooler And More Effective Heroes, then Kinda Selfish Mercenary Heroes, then Ruthless Protection Racket.
- Locked into Strangeness: Like his brother the Lightning Beasts shocked him and his eyes and hair changed.
- Morality Pet: for Mekt in "Chained Lightning". Many years ago, dead little sister. Then, Not Quite Dead (which puts Even Evil Has Loved Ones back into play), followed by Unexplained Recovery. As he directly contributes to Ayla's restoration, he surrenders to prison without a fight.
- Psycho Rangers: Each member is a counterpart for a Legionnaire.
- Esper is a telepath like Saturn Girl
- Hunter and Timber Wolf are both bestial metahumans.
- Lightning Lord and Lightning Lad both have the ability to fire bolts of electricity.
- Ron-Karr and Wave - Bouncing Boy and Triplicate Girl (as the team's ship crew)
- Tyr claims to have powers matching Superman's.
- Tomato in the Mirror: Ron-Karr goes through this in "Who Am I?" when he is revealed to be impersonating Superman to infiltrate the Legion for Imperiex.
Voiced by: Phil Morris
- Big Bad: He is the main villain of the second season.
- Chest Blaster: He is part cyborg and has a cannon in his chest that fire an extremely powerful energy beam.
- Conqueror from the Future: He comes to the 31st century from the 41st century.
- Dual Wield: His combat style is using two energy swords at once.
- Evil Sounds Deep: He speaks in a deep and menacing voice.
- From Nobody to Nightmare: Imperiex was nothing more than a slave bred for combat until he climbed his way to power.
- Galactic Conqueror: He's out to conquer the galaxy and crush anyone who stand in his way.
- Generic Doomsday Villain: Doesn't have any personality aside from wanting to conquer everything.
- Hijacked by Ganon: Ultimately, Imperiex is not the one the Legion must deal with in the end as he gets killed by the original Brainiac.
- Hoist by His Own Petard: He planned on Brainiac 5 being taken over by his predecessor to form an alliance, but then gets usurped and killed due to said attempt at an alliance.
- In-Name-Only: Comic book Imperiex was a present-day Energy Being in a suit of armor, so giant that most of the time you were Fighting a Shadow; Animated Imperiex is a human-sized alien cyborg from 41st century.
- Impaled with Extreme Prejudice: He is stabbed in the back by Brainiac 5. While that doesn't kill him, his most powerful weapon is destroyed.
- Knight of Cerebus: His introduction significantly darkens the series, being a far more technologically advanced, ruthless overlord than what the Legion typically deal with.
Voiced by: Tara Strong
- Bald of Evil: Near the end of her debut, she gets caught in an explosion that makes her lose her hair. However, she is shown to have her hair growing back when she's later seen in jail.
- The Cameo: Makes an appearance in "Sundown" as an inmate of Takron Galtos.
- Canon Immigrant: Alexis was originally created for this show, but then she was officially introduced into the DC Universe in Grant Morrison's The Multiversity series.
- Desperately Looking for a Purpose in Life: Claims so. By the end of her episode, she decides that her purpose is to get even with the Legion. Unfortunately, she never gets another appearance beyond a cameo, so maybe she changed her mind.
- Evil Redhead: She has red hair and is very much like her ancestor Lex.
- Fiction 500: She is rich enough to own a planet, or so Saturn Girl claims.
- Jumping Off the Slippery Slope: Crosses into straight-up villainy when she tries to kill Superman over rejecting her.
- Lonely Rich Kid: She claims this is the case, but given her possessiveness once she finds a friend, one wonders if she did have friends who were chased away by her Yandere clinginess.
- Mini-Mecha: She fights in a mecha near the end of her episode.
- Never My Fault: It's a Luthor thing.
- Rich Bitch: She thinks Superman spending time with her is more important than him helping the Legion with their missions.
- Yandere: She does not take Superman rejecting her well.
Voiced by: Harry Lennix (Season 1), Dorian Harewood (Season 2)
- Abusive Dad: If experimenting on your own son isn't abusive, then nothing is.
- Actually a Doombot: A variation occurs in "Cry Wolf" when it turns out that the Dr. Londo the Legion and Timber Wolf confront at the end of the episode is just a clone and that the real Dr. Londo has long fled the area.
- Adaptational Villainy: In the original comic series, he was only used for the purpose of flashbacks with little if any character development but when the animated series came along he may be as bad of a parent as Ozai.
- Archnemesis Dad: To Timber Wolf, if he's got an episode to himself expect Dr. Londo to be the main villain
- Evilutionary Biologist: He mutated his son and several animals in an attempt to breed formidable soldiers.
- Evil Counterpart: To President Winema Wazzo believe it or not:
- Both have titles in front of their names, related to their professions and are referred to as such (President Wazzo and Dr. Londo)
- They are single parents to their children (who're the same gender as their respective parents)
- Their children are in the Legion of Superheroes and are close friends.
- Their children resemble them in some way (for example, take away the werewolfism and his son has his facial features and hair. In a few glimpses of his son's human form he does look like a younger version of his father)
- They both meddle in their children's lives. The key difference is Winema is well-meaning and ultimately wants what's best for her daughter while Londo only is interested with what he wants and doesn't care what happens to his son, he just wants his weapon/general.
- Guinea Pig Family: He experimented on his own son.
- Jumping Off the Slippery Slope: At first appears as a lone, grieving scientist who's lost everything to the creature in the forest. As it turns out his son isn't dead but is the creature Londo told the Legion about. He also attempts to kill/capture the Legion and take his son back by force using his animal test subjects.
- Karma Houdini: One of the very few villains of the series not to be either imprisoned on Takron Galtos, sent to the Phantom Zone or killed. His second and final appearance in the series ends with him escaping from the Legion and still at large.
- Lean and Mean: He's very gaunt and quite devoid of redeeming qualities.
- Manipulative Bastard: Uses the Legion to capture his son, and during Timber Wolf's calling the old man out routine in S2 he points out that his father uses everyone this way
- Meaningful Name: His first name is Mar. The word "mar" means to harm or ruin something, which is appropriate because of how harmful his experiments were to his son and his other unwilling test subjects.
- Morally Ambiguous Doctorate: He experimented on his son and local wildlife without any concern for their well-being.
- Never My Fault: Thinks Timber Wolf should be thanking him for changing him into a werewolf-monster.
- Professor Guinea Pig He cloned himself at least three times in his second appearance
- Reverse Arm-Fold: He quite often has his arms behind his back.
- Skunk Stripe: Like father, like son
- Slasher Smile: Shows this during his Villainous Breakdown when he frees his mutated animals to attack the Legion and his son. Needless to say it doesn't turn out so well, for him
- We Can Rule Together: Does this in 'Cry Wolf' with his son except it involved having to use a mind controlling device and giant golems to pummel him. Great parenting.
Voiced by: Corey Burton
- Bald of Evil: As is traditional, he has no hair. When Brainiac 5 takes damage while he's stealing his body, Brainiac 5's base body loses its hair as it undergoes repairs.
- Big Bad: Outright murders Imperiex and then takes control of his operations.
- Composite Character: He combines his comic self's color scheme with his DCAU self's voice and robotic nature.
- Enemy Within: Being Brainiac 5's predecessor, he is inevitably in his programming, but was left dormant. When Kandor was invaded by Imperiex, Brainy decided to ask for his assistance, which means Brainiac 1.0 got a foothold in his mind, which is exactly what Imperiex wanted.
- Knight of Cerebus: Perhaps even moreso than Imperiex. Namely, his first appearance in Brainiac 5's head was followed by a number of Breather Episodes, and after those were done, he then became the central antagonist in the ending two-parter.
- Not Quite Dead: After all is said and done in Season 2, it cuts back to Brainiac 1.0 putting himself back together in a new body, completely separate from Brainiac 5.
- Red Eyes, Take Warning: He has red eyes and it should be a clue to be wary of him.
- Secondary Color Nemesis: Green "skin", purple armor.
- Villainous Breakdown: He starts attacking far more aggressively when Brainiac 5 gains control again, and then screams after being impaled.
- Walking Spoiler: It's difficult to bring him up without spoiling how the second season ends.
Voiced by: April Winchell
- Amazingly Embarrassing Parents: Her daughter gets annoyed whenever she goads her to ask boys out.
- Doting Parent: She loves her daughter dearly.
- Good Counterpart: To Dr. Londo
- Gray Eyes: Like mother, like daughter
- Mama Bear: Defended her daughter against a Corrupt Corporate Executive in the Legion of Superheroes comic-adaption of the TV series
- Meddling Parents: She means well but she's very interested in her daughter's dating life
- Reasonable Authority Figure: She knows that her daughter and the other Legionnaires are doing the right thing.
R. J. Brande
Voiced by: Lex Lang
- Good Parents: Is proud of his Legionnaire son, Chameleon Boy
- Fiction 500: He is said to be one of the richest people in the galaxy.
- Honest Corporate Executive: He owns a Sun Nursurey and is thankful to Saturn Girl, Lightning Lad and Cosmic Boy for saving his life and helped fund the Legion of Superheroes
- Reasonable Authority Figure: He trusts the founding members of the Legion for saving his life.
- The Team Benefactor: He gives the Legion of Super Heroes their funding.