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Inhabitants of New York
April's scientist father who gets kidnapped by the Kraang.
- Brainwashed and Crazy: In the last three episodes of season one before the Turtles are able to snap him out of it.
- Butt-Monkey: His misfortunes include being kidnapped, being rekidnapped, having his mind controlled, and turning into a mutant that has to be caged. And then when he's finally cured, only a few episodes after that he winds up getting mutated again and then he's killed in the Triceraton's destruction of Earth.
- The Cameo: He appears in "Owari" during Splinter's funeral scene, along with the Mighty Mutanimals, Chompy, Ice Cream Kitty, Shinigami, and Dr. Cluckingsworth.
- Canon Foreigner: He was more or less created for the series.
- Comic-Book Movies Don't Use Codenames: He only gets called Wingnut in his first mutated appearance, but does not go by the code name in later episodes.
- Dating What Daddy Hates: Casts a rather nasty look when he sees Casey and April leaving the movies together.
- Disappeared Dad: A non-fatal example to April, be it thanks to being kidnapped by the Kraang or being mutated (see Status Quo Is God below). This actually does become a fatal example after the third season finale in which Kirby is killed in the destruction of Earth.
- Distressed Dude: Was a captive of the Kraang during the first season, and doesn't take the Kraang's invasion during the second season finale very well. He's later understandably panicked when his daughter has been poisoned by Karai.
- Fiery Redhead: Inverted. His teenage daughter is a lot more fiery than he is.
- Played more straight in "The Gauntlet" and "The Deadly Venom", however. See Papa Wolf.
- Forgotten Fallen Friend: He's never mentioned during the arc at the farmhouse despite having been mutated by the Kraang, and April only suddenly remembers him at the end of said arc.
- Kidnapped Scientist: One of many.
- Mythology Gag: He was most likely named after the character Kirby from the original comics and 2003 series, who in turned was based on Jack Kirby. After turning into a bat Mikey calls him Wingnut, a reference to a Bat alien from the 1987 series and Archie comics. The name doesn't stick, though.
- No Celebrities Were Harmed: He looks a lot like Joss Whedon.
- Out of Focus: In season four, he's largely irrelevant to the plot, and only makes a voiceless cameo at Splinter's funeral.
- Overprotective Dad: Largely averted, as he doesn't show any issues with April fighting the various mutants and oddities of New York until "The Deadly Venom", when it seems the Hamato Clan is failing to save her life.
- Papa Wolf: In "The Gauntlet" and "The Deadly Venom".
- Red Herring: The show leads us to believe that the Kraang need Kirby for their plans, but it's revealed in "TCRI" that the person they really need is his daughter, April.
- Senseless Sacrifice: In "The Mutation Situation", he shields April from getting hit by a falling can of mutagen, causing it to break on him and turn him into a bat. However, it later turns out that due to being experimented on and having Kraang DNA April is immune to mutagen, which means his attempt to protect her turned out to be completely pointless.
- Status Quo Is God: The show seems averse to featuring Kirby as a stable presence in April's life in favor of focusing on her interactions with the Hamato Clan. He spends the majority of season one captured by the Kraang and gets mutated into a feral monster in the second season premiere, leaving April fatherless again. When he's finally returned to normal late in the second season, what does the show do to him when he and the others try to escape New York in the season two finale? Mutate him again and send the kids off on their own. He also is barely in the third season and is killed by the Triceratons along with the rest of the supporting cast while the kids once again flee the Earth without him.
- Tragic Monster: His mutation into a giant bat in "The Mutation Situation". He is finally restored to his human form in "The Lonely Mutation of Baxter Stockman"... Only to get mutated again in the second season finale, and is only restored in "Battle for New York". Considering how long his last stint as a human lasted, it may not be a stretch to imagine that he'll be mutated again, except he's killed with the planet instead.
- Vagueness Is Coming: His warning to April in "The Gauntlet" is just that something terrible is about to happen.
- What Happened to the Mouse?: Even though the Turtles managed to save the earth from being destroyed in season four, thus saving Kirby's life, he's never seen again after this, and only mentioned once by Mikey.
- He eventually makes a background appearance alongside many other allies for Splinter's funeral.
- What the Hell, Hero?: He angrily lashes out at Donnie when the turtle can do nothing to help his poisoned daughter and demands to take her to a real hospital. And he does this again to Splinter when it seems his efforts are equally fruitless.
A robot turtle made by Donatello to fight in his place after he gets tired of breaking his bo staff. Later rebuilt as the ultimate sparring partner.
- Adaptational Heroism: In the previous incarnations, Metalhead is usually built by the villains in order to destroy the Turtles. Here, the Turtles built him, trying to destroy them was unintentional. Double Subverted once he has advanced AI later on. He seemingly betrays the Turtles, except that it was in their best interests since he just wanted to help them free mutants and ultimately sacrifices himself for them.
- A.I. Is a Crapshoot: Subverted, in his debut, Metalhead is just a drone, and when his connection to Donnie is severed, a Kraang takes control of it and turns it against the Turtles, and Donatello must destroy it. After he's been rebuilt Donnie installed a rudimentary AI in him, and he remains docile.
- In "Metalhead Rewired", he upgrades the AI and the trope seems to be played straight when he reneges to join the Kraang, but it's once again a subversion as he was doing so to free all their prisoners.
- Arm Cannon: One of the various weapons in its arsenal.
- Badass Adorable: At least Michelangelo sees him this way.
- Back for the Finale: He gets rebuilt to take on the Kraang in "Showdown".
- Balls of Steel: Mikey tries to take him down with a Groin Attack, with predictable results.
- Berserk Button: According to Donatello, he "doesn't like being tickled".
- The Cameo: In "The Pulverizer" and "TCRI".
- Curb-Stomp Battle: He dishes out two, first to all the Turtles except Donnie (which Donnie even lampshades), and then again to a group of Kraang that only ends when Donnie loses Metalhead's signal after his antenna breaks off.
- Death by Irony: Aside from being destroyed his own creator, he's also taken down with the very weapon that Donatello's dissatisfaction with led to his creating Metalhead in the first place.
- Energy Weapon: Metalhead's primary weapon. Notably when Donnie is in control the lasers are bluish white, but when the Kraang take control the lasers become the same fuchsia color of the Kraang's weapons.
- Fire-Breathing Weapon: Metalhead can switch out his lasers for a flamethrower.
- Grew Beyond Their Programming: Examined in "Metalhead Rewired". Donatello upgraded Metalhead with an intelligent A.I. capable of learning, for the purpose of becoming the ultimate sparring partner with the Turtles. However, it then goes to seemingly betray the Turtles and fall under the thrall of the Kraang, only for it to be revealed it was an elaborate ruse so Metalhead could assist the Turtles in saving the mutants and even knowingly performs a Heroic Sacrifice, showing that beyond capable of deception and formulating plans, Metalhead has become not just self-aware, but sentient, making the choice to sacrifice himself for the well-being of his comrades. Foreshadowed on his developing personality throughout the episode, such as a thumbs-down to taunt Leo during sparing and a thumbs-up to reassure his comrades.Donatello: I programmed him to be intelligent, but... I hadn't realized how much he had evolved.
- HeelFace Revolving Door: Starts out as Donatello's robot, then gets hi-jacked by a Kraang, and then gets rebuilt to fight for the Turtles again.
- Heroic Sacrifice: Keeps the portal open so the Turtles can escape, even though it means he'll be destroyed by the Kraang.
- Hoist by His Own Petard: He was destroyed by his own creator. Not only that but Donnie also used Metalhead's own weapons against him during their fight.
- Impaled with Extreme Prejudice: He's finally disabled when he's driven into the broken half of Donnie's bo staff.
- No Indoor Voice: Comedic justified example. Due to Donnie's inability to control the speakers inserted into Metalhead, he often winds up being way louder than necessary. This is fixed later on.
- No-Sell: Metalhead is shown to be completely immune to nearly all forms of harm, including multiple attacks from Leonardo's katana and repeated shots from the Kraangs' laserguns.
- Pint-Sized Powerhouse: He is noticeably shorter than any other character in the series thus far, even Raphael.
- Promotion to Opening Titles: Appears walking around Donnie's lab in the season two opening.
- Robot Buddy: To Donatello, the rest of the Turtles don't take to him as well. They do warm up to him in Metalhead Rewired when he sacrifices his life for them.
- Robotic Psychopath: After the Kraang take control of him.
- Rocket Punch: His fists can be launched as guided projectiles.
- They Killed Kenny Again: He's pretty death prone, but Donatello always rebuilds him.
- Walking Armory: Frickin' Laser Beams, Fire-Breathing Weapon, Rocket Punch, Macross Missile Massacre... he's pretty much got it all.
- We Need a Distraction: Serves this role in "Showdown".
- With Cat Like Tread: One of the initial problems with Metalhead is that it was incapable of running around without producing thunderous stomps that set off all nearby car alarms.
A blind noodle chef targeted by the Purple Dragons and later the Foot.
- Blind and the Beast: April takes the Turtles to Murakami's restaurant specifically because he is blind and can't see that they aren't human. He later figures it out through his other senses, but is not afraid and is very grateful to them for saving his life.
- Blind People Wear Sunglasses: He sports a pair of round ones.
- Canon Foreigner: He was created for the series.
- Cool Old Guy: He seems to be an understanding, reasonable, and nice guy in addition to being a great chef.
- Distressed Dude: How the Turtles' met him and after Xever captured him.
- Handicapped Badass:
- While not much of a fighter, his style of cooking makes him "a ninja, but for food." He was even able to create a brand new distinct recipe — pizza gyoza — on the spot as thanks for the turtles saving him from the Purple Dragons, something that becomes his most popular dish.
- When Karai gets into his shop, he's quite suspicious of her, especially her order of Turtle Soup. When a fight breaks out, he throws the soup in her face and stalls her long enough for April to escape, all the while pretending to be a klutz via blindness.
- Innocent Bystander: His primary role in the series.
- Supreme Chef: Two words. "Pizza gyouza."
A Turtles Fanboy who is desperately attempting to be a superhero.
- Aborted Arc: He was more or less almost completely forgotten after "Mutagen Man Unleashed". The closest he might get to a resolution is his empty container being seen in a battle cage in the "Raphael: Mutant Apocalypse" arc, but the writers and Nickelodeon have said that the aforementioned story arc is not canon.
- Adaptational Badass: The 1987 Mutagen Man only had the ability to transform into other people temporarily. This Mutagen Man has Hollywood Acid and gets more dangerous when he drinks Mutagen, acquiring actual control over the acid and super strength, along with a natural affinity for being Nigh Invulnerable.
- Adaptational Villainy: This Mutagen Man is far more psychopathic and dangerous than his 1987 counterpart.
- Appropriated Appellation: He calls himself Mutagen Man when told to stop stalking April, most likely remembering Mikey's nickname for him.
- Ascended Fanboy: Of the Turtles.
- Badass Boast: He gives some good ones to the Purple Dragons, but he can't really follow up on them.
- Badass Normal: Subverted. He's an awful excuse for a fighter who only tries to be a Badass.
- Be Careful What You Wish For: He wanted desperately to become a mutant and as the Turtles explicitly point out in the episode, he got his wish.
- Blessed with Suck: His transformation into Mutagen Man in a nutshell. While being far more resilient to physical harm, he needs mutagen to continue fighting.
- Body Horror: Upon his transformation into Mutagen Man, his body is a slimy clear liquid with his brain and other organs visible, his eyes and lips are on top of stalks.
- Brain in a Jar: As Mutagen Man.
- Canon Character All Along: He appeared to be a brand new character loosely based on the character Zach of the 1987 series. Then he foolishly allows himself to be mutated into a monstrous blob, making him the new identity of the character Mutagen Man.
- Cannon Fodder: The Foot Clan drafted him as this, but he was too stupid to know what the Japanese term meant and didn't even know what the actual term in ENGLISH meant.
- To clarify, they gave him the rank of 'ashigaru sah' to his face. The more precise translation is 'borrowed footsoldier'.
- The Chew Toy: Almost every scene he has ends up treating him like this, especially his transformation into Mutagen Man. He almost always puts it on himself though, being Too Dumb to Live.
- Cloud Cuckoolander: He isn't the brightest boy, is the Turtles' personal Loony Fan, and his plans don't make that much sense most of the time.
- Combat Tentacles: His arms become these after his transformation into Mutagen Man.
- Composite Character: Of Zach from the 1987 series (a turtle fanboy who tries to help, only he's much less useful) and Mutagen Man.
- The Ditz/The Fool: Even more so than Mikey. Splinter even calls him a doofus.
- Driven to Madness: Possibly. Its not clear if he turned on the Turtles because he blamed them for what happened or because he's just feral now.
- FaceHeel Turn: The mutation makes him feral.
- Failure Hero: He wants to be a hero like the Turtles but has none of the skills or training required to be one so his attempts to "help" the Turtles often do more harm than good.
- Fat and Skinny: The fat to Donnie's skinny.
- Fat Idiot: Well, he appears overweight. This makes his attempts at being a hero look even more pathetic, too lazy to put in all the training and work needed to be a vigilante, and too dense to see why it is necessary no matter how much Donnie tries to teach him. He even happily confesses to wearing muscle padding under his Turtle hero suit.
- The Friend Nobody Likes: To the Turtles. Whenever he comes along, he always ends up making their job twice as difficult.
- From Nobody to Nightmare: After being doused with mutagen, he becomes Nigh Invulnerable.
- Heroic Wannabe: As mentioned he wants to be a hero just like the Turtles, hence his (amateurish) superhero-like costume based on an 1987 series' designs of the Turtles. Unfortunately for everyone involved, he doesn't realize that to be like the Turtles requires years of strenuous training, not just a cool costume.
- Hidden Depths: During his training montage with Donnie, he made a picture of himself with muscles on a sketch pad that was well drawn and mentions driving/delivering ice cream from a truck which at the very least requires a driver's license.
- Hollywood Acid: His whole body's made of it as Mutagen Man.
- Hulk Speak: As Mutagen Man.
- Idiot Hero: Deconstructed rather horrifically in the end. Due to being Too Dumb to Live he becomes a mutant nobody is happy with and even presumably blames the people who did everything to prevent that from happening.
- Killed Offscreen: In the non-canon "Mutant Apocalypse", his container can be seen during a cage match. If it's not prop recycling, it means Timothy is likely well and truly dead in that universe.
- Knight of Cerebus: In a tragic way. His mutation into Mutagen Man is played Dead Serious with no jokes at his expense unlike previous victims. Mikey even stops joking after seeing what a Tragic Monster he had become, only snarking when Leo ordered a distraction; even then, he still talked in a rather somber manner.
- Lantern Jaw of Justice: Since his design seems to be a parody of standard superheroes.
- The Load: To the Turtles, especially Donatello, who ends up having to train him.
- Mobile-Suit Human: He gets this as a means of moving around.
- Multilayer Façade: He still wears his turtle uniform under his Foot Clan uniform.
- Never My Fault: As of "Mutagen Man Unleashed", his sanity has deteriorated to the point where he blames the Turtles for his mutation.
- Nigh Invulnerable: As Mutagen Man, his body is acidic and impervious to harm.
- Loony Fan: Of the Turtles.
- The Mole: Becomes one to the Turtles while with the Foot Clan. Not that he's that great at it though.
- Ninja: He joins the Foot Clan, albeit as a glorified errand boy and Cannon Fodder.
- Promotion to Opening Titles: He shows up in the season two opening as Mutagen Man in Donnie's lab.
- Running Gag: "The Pulverizer Returns" sees him twice running off down the same alleyway and causing a car crash both times due to his complete inability to be stealthy.
- Too Dumb to Live: Him trying to expose himself to the mutagen despite being warned how dangerous it is. Particularly egregious since Donatello repeatedly tried to save him from being turned into a Mutant yet he still willingly subjected himself to it.
- Tragic Monster: The most tragic of them all. Not even the Shredder was treated as seriously as him after his mutation.
- Unskilled, but Strong: It's pretty clear that Mutagen Man isn't very smart, but he makes up for it with super strength, incredible difficulty to take damage, and his Hollywood Acid.
- Vader Breath: He's given a synthetic voicebox to allow him to speak as Mutagen Man, though the result is scratchy and labored.
- Walking Spoiler: For a time he rivaled the Rat King for how much of his character folder was whited out.
- What Happened to the Mouse?: At the end of season two, Donnie was forced to leave him in his lab as the Turtles fled from the Kraang. Even though the Turtles reclaimed the lair in season three, he was never seen again. Making this more jarring is the fact that his empty containment tank was still in Donnie's lab even in later seasons.
- What the Fu Are You Doing?: Since he wants to be like the Turtles he tries to fight like them even though he has little practice or patience to learn how to use ninjitsu correctly, which is why Donnie tried to act as his "Sensei".
- Whole Costume Reference: His costume looks like the Turtles from the 1987 series, right down to the letter on the belt.
- Wrong Genre Savvy: In both of his first appearances. He thinks the Turtles are actually humans dressed as turtles, which isn't uncommon. He thinks he can be a skilled Badass Normal yet ignores practice, resulting in him getting taken down very easily. He also joins the Foot, thinking they are the good guys because they hunt the Kraang and made him a ninja because they were impressed, but learns they're actually evil and made him their cannon fodder. He also thinks mutagen will make him a superhero that can help the Turtles fight the Shredder, but because the mutagen's effects are unpredictable, he becomes a mindless blob monster.
A Channel 6 news reporter.
- Alliterative List: Loves slipping these into her stories."Are malicious mutants menacing Manhattan?"
- Canon Foreigner: She was created for the series.
- Chuck Cunningham Syndrome: She was last seen getting attacked by Mega Shredder.
- Exhausted Eye Bags: Always has these.
- Graceful Ladies Like Purple: Wears a purple suit with a violet shirt underneath.
- Red Shirt Reporter: Will sometimes put herself in danger to report a story.
- Secret Chaser: Almost exposed the Turtles.
- Unfortunate Name: Her last name is another word for "gross".
- You Don't Look Like You: In the story book Mikey's Monster, adapted from the episode "It Came From the Depths", she looks absolutely nothing like she does in the show◊.
- Adaptation Dye-Job: Irma's hair is black in this series as opposed to being a brunette like in the 1987 series. However, the hair color and style is based on her brief appearances in the Archie comics.
- Adaptational Villainy: She goes from being a trusted ally in the 1987 series to The Mole.
- Curb-Stomp Battle: Loses to Splinter in a matter of minutes.
- Early-Bird Cameo: Doesn't show up in person until midway through the second season, but a closeup picture of her eye can briefly be seen on April's cellphone in "Mousers Attack!"
- Encyclopaedic Knowledge: She rattles off a lot of information about rats off the top of her head, carrying over as The Smart Girl of the human allies from the 1987 series.
- Hidden Depths: She also has something inside her like April as revealed in "A Chinatown Ghost Story". The season two finale reveals that she's actually a drone being piloted by Kraang Sub-Prime, explaining Ho Chan's confusion.
- The Klutz: Though not as much as her 1987 counterpart. Subverted, as it may have been an act.
- The Mole: She was in reality Kraang Sub-Prime the entire time April knew her.
- Motor Mouth: As a function of being a walking encyclopedia. See above.
- Perky Goth: Has this aesthetic.
- Picky Eater: She appears to be gluten-sensitive. Maybe it damages the robotic suit.
- Ridiculously Human Robot: Turns out she's a Kraang exosuit.
- Robotic Reveal: She's actually a Kraang Mini-Mecha.
- Surprisingly Good English: Compared to most of the other Kraang. Kraang Sub-Prime is even seen complaining that in the thousands of years the Kraang have been on Earth, he's the only one who has bothered to learn how to speak English properly.
- Walking Spoiler: Oh yeah.
- Younger and Hipper: Like April, Casey, and Karai, Irma is a teenager in this adaptaton.
A larper obsessed with the role-playing game Mazes and Mutants who became a sparrow mutant after exposure to one of the scattered canisters of mutagen. He attempted to make the Turtles play with him by having them fight for their lives in a mental construct. After his game was beaten, the Turtles told him to stop forcing other people to play with him and parted with him on good terms.
- Alliterative Name: His real name is Martin Milton.
- Anti-Villain: He may have put the Turtles through a lot of trouble, but in the end he only wanted other people to play with him.
- Author Appeal: The creators created him due to expressing interest in a "magic" character, and the role playing games they played in their youth.
- Canon Foreigner: He was created for the series.
- Handicapped Badass: He is missing a leg, which he has replaced with a wooden stick.
- Heel Realization: He is forgiven by the Turtles when he realizes that he shouldn't force people to play his game.
- Was Once a Man: He is first seen in his mutant sparrow form. We don't find out that he used to be human until he later tells the Turtles his story near the end of the episode.
- Whatever Happened to the Mouse?: He was never seen again after his debut episode. Rumors circulated he was part of the Mighty Mutanimals before the episode revealed it consisted of Leatherhead, Slash, Pigeon Pete, and Dr. Rockwell. Furthermore, he was absent in "Annihilation Earth!", despite other characters such as Mondo Gecko appearing.
- Your Mind Makes It Real: His powers in a nutshell.
Jack J. Kurtzman
He is first introduced in "The Kraang Conspiracy". April senses that somebody is watching them during a night time roof top training run, so they chase him down to his apartment where he tells them why April is so special to The Kraang, and that The Kraang have been on Earth for thousands of years. He later returns in "The Manhattan Project" and tells them the recent bout of earth quakes are being caused by giant alien worms called Kraathatrogon, which The Kraang milk like cows for mutagen.
- Big Good: When the Turtles fled New York after the Kraang conquered New York, he became the benefactor to the Mighty Mutanimals and coordinated their campaigns.
- Camera Fiend: Has a bunch of pictures of The Turtles, April O'Neil, The Kraang, and many of the other mutants, justified since he is hot on the trail of The Kraang Conspiracy.
- Canon Foreigner: He was created for the series.
- Hero of Another Story: Like the Turtles, he's on his own Anti-Kraang adventures, which aren't detailed, but he's been as successful as the Turtles have so far. (Enough that the Kraang are already well aware of his name and who he is by the time we meet him)
- Intrepid Reporter: States that he started out investigating why scientists were disappearing, and it led him to discovering The Kraang.
- The Mentor: To Slash, and by extension the rest of the Mutanimals.
- Private Detective: Primarily of the Occult Detective variety. His business card clearly states that he is an investigator and writer concerning the occult, extra-terrestrials, and the supernatural. This is his card◊.
- Shout-Out: Named after Jacob Kurtzman, AKA Jack Kirby.
- His wardrobe is very similar to that of Carl Kolchak.
- Stalker Without a Crush: Has been stalking The Turtles and April O'Neil for quite some time, a fact they are initially very creeped out about.
- What Happened to the Mouse?: His fate is unknown by the end of season two, what with the Kraang successfully taking New York. Turns out he successfully evaded the Kraang for several months, and became the Big Good for the resistance.
The Mighty Mutanimals
- Chekhov's Gunman: The founding members were all introduced well before there was any indication they would become a team. Some supporting characters, one a former villain, and another just a bit part.
- Flawed Prototype: Slash wanted to form his Secret Mutant Hero Team to be better than the Turtles with just him and Raphael. When he couldn't get Raph to defect from the Hamato Clan, he paired up with Newtralizer. When Newtralizer was seen to be Ax-Crazy Slash disappeared and then resurfaced with a fully formed team.
- Hero of Another Story: The Mutanimals waged a months-long war against the Kraang during their occupation of New York until the Turtles returned to the city.
- Mythology Gag / Call-Back: Shares the name and (eventually) teammate Mondo Gecko with a spin-off team from the Archie comics series.
- Similar Squad: Perhaps intentional in a subconscious way. Slash wanted his own team from the day he mutated. The one he made has many explicit parallels to the Turtles since he grew up in their household. He even states that he modeled his leadership style after Leonardo.
- The Team: A Similar Squad that parallels the Turtles. Slash is in the "Leonardo" / Leader role, Leatherhead is the "Raphael" / aggressive second in command role, Rockwell is the "Donatello" / genius role, and Pigeon Pete is the "Michelangelo" / foolish comic relief, until he's replaced by Mondo Gecko who fits the same archetype while being less annoying and weird.
A mutant Turtle with a vendetta against Raphael's brothers and tries to become his new "partner". Eventually goes on to found the Mutanimals and is the faction's leader as a whole.
- Adaptational Heroism: He's the first version of the character to be on the side of the Turtles instead of being part of their very large Rogues Gallery, much like in the Archie comics.
- Adaptational Intelligence: He's generally portrayed as Dumb Muscle in other incarnations. Here, he has a keen tactical mind that allows him to practice Ninjitsu effectively, and lead a team of mutants of his own.
- Anti-Hero: After his HeelFace Turn.
- Anti-Villain: Established in "Newtralized!" when he refuses to kill humans in order to defeat the Kraang.
- The Atoner: It's implied that Slash's founding of the Mighty Mutanimals is a form of penance for his misdeeds, particularly during his debut episode. He's clearly ashamed of his ways back then when confronted by Leo over it and claims that the mutagen drove him insane.
- Ax-Crazy: While normally similar to Raph on a good day, pressing his Berserk Button reveals the monster underneath.
- Battle Trophy: He takes Mikey and Donnie's bandanas after beating them down and wears them as arm bands on his right arm, until Raph takes them back.
- Berserk Button: Being called a monster or being rejected by Raph makes him drop his Mask of Sanity.
- The Berserker: While he's normally a pragmatic, efficient, and intelligent fighter, pressing his Berserk Button makes him go feral.
- Blood Knight: To an extreme degree, he makes Raph seem soft.
- Canon Character All Along: While originally introduced as Raph's non-sapient turtle Spike, who served as a Canon Foreigner, he is mutated into what he is now.
- Carry a Big Stick: He has a GIGANTIC mace is his Weapon of Choice.
- Characterization Marches On: It's almost hard to swallow that a character who's had tropes like Knight of Cerebus, Ax-Crazy, and Sadist listed in his section has now pulled a HeelFace Turn.
- Classic Villain: He initially represented Pride, Envy, Wrath, and Lust.
- Combat Pragmatist: He totally avoids a direct fight with two Turtles and instead snuck up on or misdirecting them.
- Composite Character: While his name and general look is still Slash, some of his visual qualities, such as his size, the spikes protruding from his body and claws, are traits more often seen in Tokka.
- Curb-Stomp Battle: He delivers one to the Turtles and arguably does a better job than Shredder.
- Dark Is Evil: Slash is heavily associated with shadows - he mutates in the dark with the only light being the glow from the mutagen, the shadow of his fangs and spikes are often framed in shots, his ability to somehow mimic Leonardo's silhouette despite the Divergent Character Evolution below etc.
- Later becomes a case of Dark Is Not Evil.
- Divergent Character Evolution: Like the Turtles, Slash has undergone a design overhaul to make him more unique: He is much, much larger than any previous incarnation, has spikes protruding from his body instead of wearing protective plating (though the spikes seen in the shell are still prominent), and, wields a large mace instead of the katana he usually is seen with. He's also the smartest incarnation of the character to date.
- Enemy Mine: He helps fight the Kraang in "Metalhead Rewired" so he, the Turtles, and the other imprisoned mutants can escape.
- Even Evil Has Standards: Before his HeelFace Turn, Slash may have had a questionable morality, but he still genuinely wanted to defeat the Kraang and save the human race. The moment when the Newtralizer made clear his callous disregard for innocent humans is when Slash's redemption began.
- Evil Is Bigger: Slash is the evil version of the Turtles and he towers over them. Subverted as of his HeelFace Turn shown in "Battle For New York".
- Evil Counterpart: His vices match Raphael almost to a tee (jealousy regarding the brothers, takes great pride in his sheer ferocity, and has a fairly bad temper), and a fighting style that is a lot like Raphael's aggressive fighting style. Unlike Raphael, he doesn't put his vices aside for anyone and doesn't even bother to tone down his aggression. Seems to have grown out of it by "Newtralized!" where he leaves Raphael and his brothers on far warmer terms than they started out. And as of "Battle For New York", has fully grown out of it, even claiming that he modeled his leadership style after Leonardo's.
- Evil Former Friend: Raph initially treats him like a Sixth Ranger. When Michelangelo meets him he might have done the same until Slash immediately beat him to a pulp right in front of Raph's face. Raph changes his mind about the Sixth Ranger thing pretty quick. Still the two acknowledge and defend each other. This changes back to a standard friendship by the time he forms the Mutanimals.
- FaceHeel Turn: From cute normal turtle Team Pet to a homicidal monster. It's implied his Start of Darkness was much earlier and mutating just gave him an outlet to express himself beyond chewing on his leaf in agreement with Raph's venting. He pulls a HeelFace Turn in time, though.
- A Father to His Men: To his Mighty Mutanimals.
- Four-Temperament Ensemble: Choleric.
- From Nobody to Nightmare: Spike's mutation from being an ordinary tortoise into becoming the homicidal Slash. It's reversed once he becomes a full-fledged hero.
- Genius Bruiser: When he wears his Mask of Sanity he outsmarts the Turtles as easily as he beats the crap out of them.
- Guest-Star Party Member: In "Requiem", he is recruited by Splinter to join him and the regulars April, Raph, and Casey during their confrontation with Super Shredder.
- Guttural Growler: Speaks with a rather deep, graveling voice.
- HeelFace Turn: A series of other events has him ally with the Turtles against Newtralizer and rethink his position a bit. He has fully done a turn as of "Battle For New York".
- Heroic BSoD: Briefly goes through this when the Mutanimals are captured by the Kraang, berating himself for not being a good leader. It takes Leatherhead giving him a You Are Better Than You Think You Are speech to snap him out of it.
- Hero of Another Story: "Metalhead Rewired" and "Newtralized!" show him as captured by the Kraang and the latter implies a few adventures with Newtralizer in fighting the Kraang. He also actively led the fight against the Kraang occupation of New York in the Turtles' absence as the leader of "The Mighty Mutanimals".
- In a Single Bound: In "Metalhead Rewired", he jumps several stories high in a Kraang base as he escapes.
- Instant Expert: Having watched the Turtles train or not, the amount of skill he shows at both battle and stealth within just a few hours of mutating is insane.
- Jerk with a Heart of Gold: He may be ruthless and violent, but he's not that bad deep down. Even after his HeelFace Turn he still can come off as rude and aggressive, but he is a really good guy now.
- Knight of Cerebus: Barring a few taunts, he's not at all funny and the beatings he gives the Turtles show more visible injuries than previous fights in the series. The Knight of Cerebus position disappears once he makes his HeelFace Turn.
- The Leader: Of the Mighty Mutanimals.
- Lightning Bruiser: You'd think with Slash's incredibly large size and massive shell that he would be at a severe disadvantage regarding his speed. You'd be wrong. And not only is he very fast and agile, he's just as good at ninja stealth as the other Turtles are.
- Mask of Sanity: He appears to be a smart, loyal, hardworking ninja who understands Raphael's position and his problems with his brothers. Too bad his mind is too twisted to understand things like how no matter how frustrating families can be that doesn't mean things would be better if they weren't around, there are more important things in life than being strong, or that caring for others isn't a weakness.
- Meaningful Rename: Spike never really liked his old name and after mutating he tells Raphael that he would prefer to be called Slash from now on.
- Mighty Roar: His Battle Cry is very impressive.
- Mythology Gag:
- He learned ninjutsu by observing Raph (and likely the other Turtles) train during his years as a pet. Just like the original Mirage Splinter did from his master.
- He also wears an initialed belt buckle, much like the 1987 turtles.
- He's a huge, dark-colored, vastly stronger mutant turtle with a viciously spiked shell, clawed fingers, and beak-like mouth, just like Tokka. And also like Tokka, he starts out seemingly evil, but he turns out to not be all bad.
- Never Hurt an Innocent: As ruthless as he is, he won't kill innocents. The fact that the Newtralizer is perfectly willing to kill innocent people to take out the Kraang leads to his HeelFace Turn.
- Noble Demon: He knows when the Turtles have won and bows out, vowing to destroy them soon. He also draws the line at killing civilians. This leads to a HeelFace Turn.
- No-Holds-Barred Beatdown: He delivered what one of the most brutal beatings the Turtles ever received in this show. We got bruises, scratches, swollen eyes, Donnie needing help to walk and a splint on his arm. To really drive home how much this trope applies, when one sees the Turtles' first fight with Shredder, he beat them pretty badly too, but they were still okay enough to run away when Shredder became momentarily distracted. Slash beat them up so brutally that Donnie and Mikey were too injured for the group to properly flee from him and the main reason they actually manage to survive their fight with him was because Slash accidentally fell off of that building's roof.
- Non-Indicative Name: Normally Slash is portrayed with swords, here his Weapon of Choice is a spiked mace, a bludgeoning weapon that actually matches his original name more.
- Pet the Dog: In "Metalhead Rewired", despite being on bad terms with Raphael, he saves his life when he could have just escaped and not bothered with Raph.
- Promotion to Opening Titles: Appears in the Rogues Gallery crawl in "The Manhattan Project".
- Sadist: It's clear that he is far more powerful than the other Turtles, but doesn't actually kill them even though he most likely can. Given his comment on how long he's wanted to hurt Leonardo, it's possible that he's actually prolonging their deaths as long as he can just because he's enjoying beating the crap out of Raphael's brothers. He has overcome this as of "Battle For New York", claiming much of it was because of his mutation.
- Sanity Strengthening: Upon his initial mutation, he had been driven crazy and wanted to kill the Turtles, believing them to be holding Raph back from being a true warrior. When he returns in "Battle for New York", he's much more stable, explaining that the mutagen had messed with his head.
- Savage Spiked Weapons: The brutal Slash INSTANTLY decides to pick a massive spiked mace as his weapon when Raphael shows off his arsenal.
- Shadow Archetype: He's Raph's shadow. Basically, he could be considered the personification of all of Raphael's hatred, rage, and love of combat unfettered by his redeeming qualities and love for his brothers. Until they DO get fettered. He becomes a counterpart to Leo instead, modeling his leadership after him.
- Spikes of Villainy: He has spikes growing out of his arms, shoulders, head, and shell...maybe he should have kept his old name, it's more fitting. No longer counts due to his HeelFace Turn.
- Suddenly Voiced: Back when he was a non-sapient turtle, Slash didn't speak. But when he was mutated by the ooze, he also gained the ability to speak.
- Took a Level in Kindness: After his HeelFace Turn, he has become a lot nicer and a caring leader to his team.
- Voice Changeling: At one point, he mimics Leonardo's voice perfectly to ambush Michelangelo. It hasn't been explained if it's one of Slash's mutant powers or if Slash can naturally do that.
- Well-Intentioned Extremist: Zig zagged. As a good guy, he has yet to do anything a normal person would consider heroic, but as a villain, he hasn't done anything malicious other than defeating the Turtles which he thought was a good thing since Raph gave him the idea that the other Turtles were lazy morons. In "Newtralized", he fights the Kraang alongside the Newtralizer. Ultimately, he takes issue with the Newtralizer's callous attitude toward hurting innocents and turns on him.
- Wolverine Claws: Nasty yellow nails.
- The Worf Effect:
- He (and the other Mutanimals) lose to Tiger Claw fairly easily in their first encounter with him.
- Zog, a Triceraton scout, defeats him (with even less effort than Tiger Claw) as a clear indicator of just how dangerous the Triceraton Empire is.
- It takes teaming up with Leatherhead to even come close to matching Super Shredder's brute strength, and is quickly taken down every time he faces off with him.
- Adaptational Dumbass: Downplayed. He's not stupid by any means, but compared with his 2003 version, he's not a genius on par with Donnie.
- The Aloner: Though Mikey attempts to break through to him, at the end of his first, second, and fourth appearances, Leatherhead is still alone. He finally overcomes this in season three when he joins the Mighty Mutanimals.
- Ascended Extra: After being a guest character for the majority of the first and second seasons, he takes on a pivotal role in the second season finale and becomes a recurring character in the third season onward.
- Ax-Crazy: When in one of his berserker rages.
- Because You Were Nice to Me: Leatherhead is this to Michelangelo because he was the only one to have treated him other than a monster. Because of this, it led to him becoming one of the Turtles' most trusted ally.
- Batman Can Breathe in Space: He doesn't need a breathing mask like the Turtles to breathe in Dimension X. Justified due to being experimented on by the Kraang for an unspecified amount of time.
- Berserk Button: Just the mere mention of the Kraang makes him fly off the handle and attack anyone close to him.
- The Berserker: If the Kraang are involved or spoken about around him he becomes one of these, much to his displeasure.
- Bloodless Carnage: He ambushes the Shredder in the second season finale and snaps him up in his mighty jaws, and mauls him and chomps on him like a chew toy, yet the Shredder suffers no visible injuries or blood loss.
- Bruiser with a Soft Center: When not in Berserker mode, he's a genuinely nice guy. He gives Slash, who was questioning his abilities as a leader, a pep talk during "Battle For New York".
- Carry a Big Stick: He wields a large club in Dimension X.
- Composite Character: He has the most in common with the Mirage and 2003 versions, as he's a heroic ally of the Turtles who deals with bouts of insanity and rage.
- Curbstomp Battle: Let's put it this way; the only fights he's been in where he is on the receiving end of this trope were against Splinter and Shredder.
- Dark and Troubled Past: He was subjected to horrific experiments by the Kraang.
- Dark Is Not Evil: He's a hulking humanoid alligator, but he's not quite nice, either.
- Defrosting Ice King: To Mikey.
- The Dreaded: Of a sort. Given his temper and instability, when the Turtles go to him for advice in "TCRI", they're all unsurprisingly scared of him.
- Early-Bird Cameo: Before appearing in the series, he was in "Dark Horizons", a flash game on the Nickelodeon website as the final boss and seeming villain of the piece.
- Four-Temperament Ensemble: Phlegmatic (except when he's angry).
- 11th-Hour Ranger: To the Hamato Clan for season two.
- Exploited Immunity: As an alligator he is semiaquatic, we see him use this to drown Rahzar.
- Game Face: He has a second set of eyelids just like the Turtles that make his eyes appear completely white when his Berserk Button has been pressed and he loses control.
- Gentle Giant: When he's in a good mood, he's nice guy who doesn't want to hurt anybody.
- Good Is Not Nice: He's bitter, anti-social, and has a Hair-Trigger Temper.
- Good Is Not Soft: Unlike the Turtles, he does not hesitate to kill, having killed a number of Kraang and drowning Rahzar.
- Guttural Growler: He has a very deep voice.
- Heroic Sacrifice: In "TCRI" where he goes through the portal to Dimension X to keep anything else from coming out of it.
- Attempts to pull it again in "Into Dimension X" but Mikey averted that one.
- Hidden Depths: While not the Genius Bruiser his 2003 counterpart was, he did construct a number of deadly traps to keep the Kraang from taking back a Mineral Macguffin he stole from them.
- Immune to Bullets: The Kraang typically fire innumerable rounds of laser fire into him. He doesn't even flinch. Possibly justified because normal alligators' scales can withstand a lot of punishment and he's a heavily powered up and mutated one.
- Jerk with a Heart of Gold: Despite his berserker rages and subsequent aloof behavior, he is a nice guy who doesn't want to hurt others, aside from the Kraang.
- The Lancer: To Slash in the Mighty Mutanimals.
- Lightning Bruiser: Fast enough to fight evenly with the Turtles and strong enough to fight Traag evenly, a 20 ft. tall rock titan that required three turtles working together to knock down. He also would've ripped the Shredder to pieces through sheer speed and brute force had he not checked on Splinter.
- Lizard Folk: As a mutated alligator.
- Metamorphosis: From baby alligator to human-gator mutant.
- Mook Horror Show: He subjects the Kraang to this in his first appearance, easily tearing them apart. Donnie sums it up best:Donnie: Never thought I'd feel sorry for the Kraang.
- Music Soothes the Savage Beast: Invoked by him in-universe. He tries to calm himself by listening to peaceful music from a record player.
- Number Two: Second-in-command of the Mutanimals.
- Odd Friendship: Develops one with Michelangelo.
- Older and Wiser: Once he comes back from an extended stay in Dimension X he's noticeably more mellow and laid-back, though he's still as tough as ever.
- One-Man Army: Him against an entire army of Kraang. Feel sorry for the Kraang.
- Promotion to Opening Titles: He's added to the opening credits as of "Return to New York."
- Reluctant Psycho: He's well aware of how unhinged he is and is not happy about it.
- Reptiles Are Abhorrent: A mild case. While he's not evil or bad, he's not the nicest of folks, and is prone to going into berserker rages that make him a danger to everyone around him.
- Running Gag: His grabbing Donnie by the face and manhandling him when in his Berserk Mode.
- Sanity Strengthening: In his first appearances, just mentioning the Kraang sends him into a berserk rage. By the time season three rolls around, he still hates the Kraang, but he saves it for, y'know, the actual Kraang.
- Sewer Gator: Before he was discovered by the Kraang, he was a pet flushed down a toilet and living in the sewers.
- Stock Animal Behaviors: When fighting the Turtles during his first appearance, he goes into a death roll.
- Took a Level in Kindness: In "Battle For New York", Leatherhead seems to have finally gotten his anger under control, as he only exhibits violence towards the Kraang. The fact that he's the only Mutanimal to not argue with the Turtles (Mikey) really says something.
- Tragic Monster: He can't control his berserker rages that are a result of the Kraang's abuse so he tries to keep his distance from others for their own safety.
- Trauma Button: The Kraang. The mere mention of them can send him into an Unstoppable Rage.
- Unskilled, but Strong: He's horrifically good at wiping out legions of Kraang, but ended up being little challenge to the skilled, experienced Shredder. He outmatches the Shredder in sheer physical power, but the Shredder attacks his pressure points, then beats him to near-death.
- Unstoppable Rage: Even he can't stop it.
- What Happened to the Mouse?: He was brutally beaten by the Shredder and kicked into freezing sewer water and his fate was unknown for the entire first half of the third season. He returns as a member of the Mighty Mutanimals alongside Rockwell, Pigeon Pete, and Slash.
- Woobie, Destroyer of Worlds: After being flushed down the toilet by his owner's parents he was captured, mutated, and tortured by the Kraang resulting in what he is today.
- The Worf Effect: After proving to be Shredder's superior in brute strength (with Shredder having to resort to pressure points to fight him), Leatherhead is barely able to slow down Super Shredder even with all of his might.
- You Shall Not Pass!: Tries for one in "Into Dimension X", but Mikey takes the choice away from him.
- Younger Than They Look: As Dimension X runs on Year Inside, Hour Outside. By the time he returns in "Into Dimension X," Leatherhead has aged several decades.
- Alliterative Name: Since he is a Pigeon named Pete.
- Ascended Extra: He appeared in the first act of "The Gauntlet" and disappeared until season three when he became a recurring character as a member of the Mighty Mutanimals.
- Attention Deficit... Ooh, Shiny!: Easily distracted by bread. Doubles as Through His Stomach. Weaponized by Slash later on, when he throws bread at his targets as though it was a weapon, generally causing a confused reaction until it attracts Pete's attention and he goes nuts.
- Big Eater: As befitting a mutated, giant pigeon, he loves chowing down on bread.
- The Bus Came Back: He returned during the third season (55 episodes after his first appearance). He later reappeared in the season four finale as one of the guests at Splinter's funeral.
- Canon Foreigner: He was created for the series.
- Exotic Eye Designs: Bulging eyeballs with red sclerae, yellow irises and horizontal pupils. This is because he was a pigeon mutate instead of a human one.
- Flight: Well, he is still a pigeon.
- Four-Fingered Hands: As a result of being turned into a human-based mutant.
- Four-Temperament Ensemble: Sanguine.
- Half-Dressed Cartoon Animal: For decencies sake, since he would have never worn clothes as a pigeon.
- Instant Messenger Pigeon: And a mutant one, at that.
- Mythology Gag: He's named after Michelangelo's pigeon friend from the episode "What's Michaelangelo Good For?" of the 1987 series.
- Non-Standard Character Design: Out of the mutants in the series, he has far more human-like aspects, such as human-like hands and an exposed chest and upper body. This is because he's a pigeon mutated into part human instead of the other way around.
- Out of Focus: He doesn't get any lines or the chance to do much in "Annihilation Earth!" unlike the other Mutanimals, and after the group's return in "Earth's Last Stand", he disappears altogether.
- Power-Up Food: Downplayed. He has the potential to be deadly and helpful, but he's usually too scatterbrained to be anything other than a scout. Throw bread at something though and he'll peck it to death to get it.
- Put on a Bus: After not doing much in the Mutanimals' only confrontations with the Triceratons at the end of season three and midway through season four, he's apparently ejected from the team offscreen before they return in "The Mutant Gangland" and returns to the bus; they "don't talk about him" when his absence is brought up.
- Trademark Favorite Food: Being a pigeon, he loves bread, mostly sourdough.
- What Happened to the Mouse?: No explanation has been given for his sudden absence from the Mutanimals starting during the middle of season four.
Dr. Tyler Rockwell
A scientist and former colleague of Dr. Falco. Used as a guinea pig for Falco's modified mutagen, becoming a mutant chimpanzee with psychic powers.
- Baleful Polymorph: Instead of giving him the appearance and attributes of a primate, the mutagen experiments that were performed on him turned him into one which, psychic powers aside, appears completely normal, showing no signs of having retained any of Rockwell's intellect or personality. It turns out he does, however, and becomes The Smart Guy for the Mutanimals.
- The Bus Came Back: Appears as a mindless animal in episode seven and a cameo thirty episodes later, before having his first speaking role in episode 64.
- Canon Foreigner: He was created for the series.
- Chained by Fashion: He has shackles on his arms, legs, and neck. Justified because he's an escaped test subject.
- Combat Clairvoyance: With justification, see below.
- The Empath: He reacts to other people's emotions, which allows April to connect with him due to possessing a similar ability.
- Expy: By "Battle for New York", he has become one to Mr. Hal Gibson from Super Robot Monkey Team Hyperforce Go!, being an Insufferable Genius monkey who is The Smart Guy of his team. They even share the same voice actor.
- Four-Temperament Ensemble: Melancholic.
- Half-Dressed Cartoon Animal: The only clothes he is wearing are what survived his transformation and captivity.
- Insufferable Genius: After he regains his intelligence, he comes off as an arrogant genius and likes to annoy Donatello, The Smart Guy of the Turtles.
- Jerk with a Heart of Gold: After he regains his intelligence, he constantly interrupts Donatello and finishes his sentences for him, basically telling him "talk faster next time". Even when the Turtles and Mutanimals reconcile in "Battle for New York, Part 1", he still takes the time to snub Donatello. However, he respects the other Mutanimals which is meaningful considering that he is the only former human in the group. He's also reluctant to surrender the portal to the Kraang in "Battle for New York, Part 2" because doing so would strand the Turtles in Dimension X.
- Maniac Monkeys: Even after the Turtles learn he's not just a mindless monster, he's still quite dangerous when angered.
- Metamorphosis: From human to mutant chimpanzee.
- The Smart Guy: The brains of the team of the Mutanimals.
- Smart People Speak the Queen's English: After he regains his intelligence, he speaks with a British accent.
- Suddenly Voiced: As a result of the Kraang boosting his intelligence, he is able to speak once more when he did as a human.
- Supernatural Gold Eyes: To indicate his unusual nature and abilities as an empath.
- Psychic Powers: In between "Metalhead Rewired" and "Battle for New York", Dr. Rockwell was experimented upon by the Kraang, increasing his psychic abilities to the point where he now can read others minds, control others minds, and levitate objects through telekinesis.
- Tragic Monster: He was just an ordinary scientist before being turned into a test subject, and now he knows the feelings of everyone around him regardless of whether its positive or negative.
- The Voiceless: Originally he was one of the few mutants in the show who couldn't talk. No longer the case as of his reappearance in "Battle For New York" due to the Kraang experimenting on him, which unlocked his higher intelligence.
- Was Once a Man: He's the only member of the Mighty Mutanimals who used to be human.
- The Worf Effect: None of his technology or powers stand a chance against Super Shredder, not even his super-heated plasma.
Muckman is Garson Grunge, a former sewer worker turned garbage man who is transformed into a lumbering mountain of muck and garbage after being hit by a canister of mutagen thrown through a window by Bebob/Anton Zeck during a fight with the Turtles.
- Ascended Extra: Garson Grunge was originally just a generic Recurring Extra who tended to encounter mutants, starting with "Invasion of the Squirrelanoids". He's since become Muckman.
- Beauty Equals Goodness: Averted. He's a hideous monster made of garbage and muck, but he's a noble and heroic person.
- Blow You Away: When his temper gets the better of him, he generates a powerful whirlwind of garbage around himself.
- Body Horror: He's covered with slime and tumours, and has a hole in his torso through which his shattered spine can be seen.
- Canon Character All Along: He was credited only as the "Sewer Worker" before his name was finally revealed, in the same episode where he was mutated.
- Composite Character: In a sense; In the 1987 series, Joe Eyeball was a separate mutant (formerly Joe Junkee, Garson Grunge's best friend). Here, he's Garson's own eyeball, which has gained a mind of its own.
- Dark Is Not Evil: While it is true that he looks like a horrifying monster, Muckman is still human on the inside and helps people in need.
- 11th-Hour Ranger: He joins the battle to save the world from the Triceraton invasion.
- Expy: Of The Toxic Avenger, with Mikey stating he'd have called him "The Noxious Avenger." He's also called a "Monster Hero", which was the original title of The Toxic Avenger.
- Four-Temperament Ensemble: Melancholic.
- Horrifying Hero: Though he certainly looks the part, the people of New York don't seem to think so. A man he saved from a mugging instantly thanked him for the rescue, showing not even the slightest fear of him.
- I Just Want to Be Normal: At first, but by the end he seems to be coming around to it, calling himself "New York's own Monster Hero."
- Man of Kryptonite: His sludge weakens the Turtles.
- Organ Autonomy: One of his eyeballs is alive and called Joe, who acts as his own personal shoulder angel.
- Poisonous Person: He can spew a blast of sewage and sludge from his mouth.
A teen named Jason, he was a normal kid who enjoyed skateboarding with his pet gecko until about a year ago, when a vial of mutagen transformed him into a gecko. He was kicked out by his parents because of this, but he takes life in stride.
- Appropriated Appellation: Zig-zagged. While he isn't impressed with Mikey dubbing him "Mondo Gecko" at first, he fully embraces the name after winning the race against Fishface.
- Borrowed Catchphrase: He asks Mikey if he can use "Booyakasha" sometimes. Mikey agrees, on the grounds that he be allowed to say "Cowabunga."
- Bullying a Dragon: Attempts to take on Hun, and later Fishface, with predictable results.
- Catchphrase: Cowabunga, also acts as a Shout-Out to the 1987 series.
- Cursed With Awesome: How he sees his mutation; aside from very mild sadness about his parents kicking him out, he actually enjoys being an anthropomorphic gecko.
- 11th-Hour Ranger: Is called in to help fight off the Triceraton invasion at the end of the third season.
- Four-Temperament Ensemble: Sanguine.
- Named by the Adaptation: The show gives him the human name of Jason.
- Non-Action Guy: While he does have the will to fight if the opportunity presents itself, his mutation granted him no particular offensive ability, and unlike the Turtles he never received any form of special training. As a result, the two times he does attempt to fight, he gets his ass kicked ridiculously fast. Lampshaded in "Requiem" when Super Shredder is utterly dominating his fight with the Mutanimals, and Mondo can only hide and sit it out.
- Parental Abandonment: His parents kicked him out after he was mutated.
- Shown Their Work: Compared to his 1987 counterpart, this version of Mondo is closer to what a Gecko looks like in real life, even sharing its need to lick his own eyeballs due to his lack of eyelids. That said, he is visually based on a Leopard Gecko which actually does have eyelids, but not sticky toe pads. And his tongue extends like a chameleon's.
- Suspiciously Similar Substitute: He takes on the comic relief / fool / "Michelangelo" role in the Mutanimals after they get rid of Pigeon Pete.
- Unwitting Pawn: To Mr. X, AKA Fishface.
A female Salamandarian (the same species as Newtralizer) who first appears in "The Moons of Thalos 3". She's even stronger and more skilled than Raphael, which is why he falls for her.
- Adaptational Badass: The original version of Mona was nowhere near this capable in battle.
- Adaptational Dumbass: Downplayed. Her original incarnation was a physics student. The Mona Lisa of this show displays no such aptitude.
- Adaptation Species Change: Human turned into a mutant in the 1987 series. Alien in this one.
- Amphibian Assault: She's a salamander-like alien and a very capable fighter.
- Appropriated Appellation: She lets Raphael call her "Mona Lisa". Partially because he can't pronounce her real name, and partially because of the flattering origin behind it.
- Contralto of Danger: Has a deep voice courtesy of Zelda Williams. Mona's also a very skilled warrior, which impresses Raph.
- Horrible Judge of Character: Considering they tried to ally with the Kraang and trusted Lord Dregg...
- In Name Only: The original incarnation of the character was a human college student who was turned into a mutant. This incarnation is an alien warrior whose name is YGythgba, and given the nickname of Mona Lisa.
- Love Interest: For Raph.
- Named by the Adaptation: Mona Lisa is indeed a nickname. Her real name in this series is YGythgba.
- No Loves Intersect: Unlike the love interests of the other Turtles, Mona Lisa's relationship with Raphael is portrayed as the most straight forward and unambiguous (Donatello and April being Will They or Won't They?, Leonardo and Karai never moving past Dating Catwoman flirting and Michalangelo having a Long-Distance Relationship across time with Renet while also flirting with Shinigami).
- Statuesque Stunner: She's almost twice the size of the Turtles, while Mikey and Raph both find her attractive.
- Token Non-Human: The only love interest of one of the Turtles to not be human or formerly human.
- Tsundere: Even before she got to know Raphael, she even shot the ice surrounding him on a cliff, while Sal Commander questions why she didn't shoot Raph instead.
- What Happened to the Mouse?: Despite Raph's suggestion that she join the Mutanimals, she's never seen with them when they make a later appearance.
- World's Most Beautiful Woman: Raph nicknames her after the painting of the Mona Lisa, which he refers to being this. It's likely she accepted it because he was calling her beautiful.
- Alien Non-Interference Clause: Why they aren't seen for the majority of the show. They've sworn not to interfere with Earth's affairs, until the Triceraton invasion and the revival of the Technodrome make it a problem too big to ignore.
- Aliens Speaking English: ...fluently. Unlike the Kraang.
- Chess Motifs: Pawn has the same designs the regular battledroids, spazzes out, and is the only one speaking in a non-American accent, but is still on the high council. Rook is deliberate, constantly referring to rigid policy. Bishop moves in mysterious ways, acting as a secret agent of sorts. Knight was the greatest hero of their people. Queen is The Leader. There is no King revealed yet, if one exists at all.
- Evil Knockoff: Bishop is revealed to be the original Norman, Rook is the original Irma. It's implied that Queen and Pawn were the original Campbell and Kraangdroid.
- Expy: Rook, Pawn, and Queen make decisions for the Utroms just as the Council of Three did in the 2003 series. They also share a blueish white color scheme. In contrast to their old incarnation, they make a point of having individual personalities instead of literally finishing each others sentences. Bishop acts as a lower level leader similar to Mortu.
- Fallen Hero: Bishop reveals that Kraang Sub Prime used to be regarded as the Utroms' greatest hero.
- Good Counterpart: The Utroms to the Kraang. Particularly Queen Utrom to Campbell, Rook to Irma, Pawn to the regular Kraangdroids and Bishop to Kraang Sub Prime. The regular Utroms are also use white versions of the Kraangdroids.
- Light Is Good: Aside from Bishop, the Utroms robot suits and human disguises are mostly white.
- Slave Race: Kraang Prime used to be an Utrom until he discovered the Kraathatragon's mutagen, deformed himself into Kraang Prime and used his new psychic powers to mind control to convert most of the Utroms into Kraangs.
- Theme Naming: Bishop introduces the rest of the Utrom Council who are named Pawn, Rook, and Queen. Put in Bishop and his reveal of Kraang Sub-Prime's former name as "Knight", and you have a chess theme. In the 2003 series only a one off Mook referred to himself as Pawn, and otherwise Bishop was the only character with a chess name.
Agent John Bishop
A chief agent of the Utroms, a heroic offshoot tribe of the Kraang who's been hiding on Earth trying to undermine the rest of his species. His human form is the template for all of the "Norman" bodysuits the Kraang use.
- Adaptational Badass: As good of a fighter as 2003 Bishop was, he was never quite able to deliver that knockout blow to the Turtles despite outclassing them to a certain degree, with most of their battles ending with Bishop fleeing after seeing the odds turn against him (or getting knocked down a shaft in their final physical confrontation in "Aliens Among Us"). This incarnation of Bishop has consistently delivered beatdown after beatdown to the Turtles either as a team, or individually in Raph's case during "Tokka Vs. The World".
- Adaptational Heroism: The 2003 Bishop was part of a Big Bad Ensemble for much of his tenure on the show. Here, Bishop is not only a hero, but he leads the Utroms.
- Adaptation Origin Connection: Averted. He is introduced separately from the Earth Protection Force, despite the fact that he was their leader and founder in the 2003 series.
- Adaptation Species Change: Bishop goes from being a human to an Utrom.
- Age Lift: The original Bishop was hundreds of years old thanks to cloning, but this Bishop is thousands of years old.
- Badass in a Nice Suit: Like most Kraang infiltrators, his Mobile-Suit Human wears a pinstripe suit and tie.
- Calling Card: A white Chess Bishop.
- Canon Immigrant: Bishop was one of the most prominent new characters to the mythos introduced in the 2003 series.
- Composite Character: In name and combat skills, he's Bishop, but as a person he's an Utrom, a benevolent alien species. The fact that he's a major leader of the Utroms also brings to mind Mortu, their leader in the 2003 series.
- Cool Shades: He wears these on his droid shell to differentiate himself from other Kraang droids.
- Dark Is Not Evil: He wears the same human disguise as the other Kraang with a pair of shades, but is an ally.
- Ditto Aliens: Aside from the shades for his human disguise, there's no noticeable difference between him and other Kraangs/Utroms whether its the human disguise or the organic pink alien.
- 11th-Hour Ranger: Swings in to help the Turtles when the threat of invasions by both the Kraang and the Triceraton Empire raises its' head.
- HeelFace Turn: He and the Utroms split off from the Kraang many years ago.
- In Name Only: The only thing he shares in common with the other incarnations of Bishop are his general appearance and name, not sharing his backstory or alignment. He's basically a brand new character using a pre-established name.
- Irony: In the 2003 series, Bishop hated aliens, barring Fast Forward. Here, he is an alien.
- Jerk Ass Ball: During his final appearance in "When Worlds Collide," he becomes a bigger douchebag than usual, particularly towards Mona Lisa and her commander, when most of the time he's presented as more of a Reasonable Authority Figure.
- Last Episode, New Character: For season three.
- One-Man Army: He can easily subdue the Turtles in a fight, and is one of their most combat-proficient allies, taking on hordes of Kraang, Triceratons, and Earth Protection Force alike.
- What Happened to the Mouse?: He was last seen fleeing his destroyed human body during the initial battle at the black hole generator, but likely got killed along with the rest of the characters. He returns in "The War for Dimension X", however it's his past self since Professor Honeycutt sent them back in time 6 months. His present self returns in "Tokka Vs. the World".
The Utrom Queen and member of the Utrom High Council.
- Aliens Speaking English: She's the only Utrom that can speak English outside of her suit aside aside from Kraang Prime and Sub-Prime.
- Royals Who Actually Do Something: She successfully attacks a Kraang ape before having her human suit electrocuted and getting kidnapped by Kraang Sub-Prime.
- Tertiary Sexual Characteristics: She wears a tiara to indicate she's female. She ALSO wears the Mrs. Campbell droid.
Another member of the Utrom High Council.
Another member of the Utrom High Council and the one who created the Irma suit until Kraang Sub-Prime stole it.
- Good Counterpart: She's one to Irma visually. Supposedly Kraang Sub-Prime stole the design for Irma's shell from her, and she's not happy about it.
- Ironic Name: In chess, the rook is represented by a tower, which she doesn't resemble in the slightest.
- Slapstick Knows No Gender: As soon as she's about to tell Honeycutt where the other black hole machine pieces are, her head is blown off by the Kraang soldiers.
Earth Protection Force
A commando unit trained to deal with alien menaces to the Earth. They first appear combating the Kraang invasion in "The Invasion".
- Adaptation Origin Connection: Averted. Unlike the 2003 series, the EPF in this series were formed long before they first encountered Bishop.
- Badass Army: They hold their own against Kraang Prime himself at one point, and later poise a serious threat to the Turtles in season four.
- Canon Immigrant: The EPF debuted in the mythos during the 2003 series.
- Imperial Stormtrooper Marksmanship Academy: Downplayed, as Splinter explicitly warns his sons that they are nowhere as buffoonish and incompetent as the Kraang could be.
- Lawful Stupid: They border on this as they refuse to listen to Bishop's well-intended warnings, and also refusing to disobey an order from General Griffin. Sure enough, they fare poorly against both Tokka and Bishop.
A general and the leader of the Earth Protection Force (E.P.F.), a global task force under the United States government whose mission is to protect Earth from any and all alien threats. Through Agent Bishop, Griffen has reached an agreement with the Utroms. In exchange for working with them, the E.P.F. have gained access to Dimension X technology.
- Canon Foreigner: He was created for the series.
- Expy: Griffen's character is based on that of Agent Bishop from the 2003 TV series. He acts as a Foil to the Utrom Agent Bishop.
- Fantastic Racism: Anyone who isn't human is on his hit list, to be eliminated sooner or later. It is even possible that he plotted to kill Bishop once his connections were no longer needed.
- Four-Star Badass: Despite his age, he managed to defeat Bishop, an alien in a bionic exoskeleton with superhuman strength, in single combat! Griffen would have killed him if Casey hadn't tasered the general from behind.
- General Ripper: His strategy against Tokka, one the six Cosmic Monsters, basically consisted of his army fighting to the finish.
- My Master, Right or Wrong: The soldiers and scientists of the E.P.F. were extremely loyal to General Griffen, even when it was obvious that his orders could end up getting them killed.
- Old Soldier: He's elderly, but he gave Bishop of all people a hard time during a one-on-one fight.
- With Us or Against Us: His attitude towards anyone who defies him, including Bishop.
Alternate Feudal Japan
A rabbit ronin who lives in an alternate feudal Japan, which is accessed from Dimension X. He debuts in Season 5 in a crossover with his series.
- Arch-Enemy: Usagi considers Jei, the black wolf, his personal nemesis after Jei murders a family, claiming he was "cleansing the world of evil". Jei returns the favor, summoning the Turtles to their dimension and brainwashing them to kill Usagi.
- Big "SHUT UP!": Usagi gives several "Be Silents" to Kintaro to keep the child in line while Kintaro is under his and the Turtles' protection.
- Blue Is Heroic: Usagi is an unambigous good guy and wears a blue kimino.
- Good Is Not Soft: As polite and patient as he is, there is no ambiguity that he leaves his foes dead.
- Hero of Another Story: He's presented as the protagonist of his story arc, with the Turtles showing up as guest stars.
- Knight Errant
- Master Swordsman: Per the course for his character, Usagi is an extremely talented swordsman; Leo, the swordsman in the Turtles, is the only one capable of fighting him to a serious degree.
- Righteous Rabbit: He's an anthropomorphic rabbit and an all around good guy.
- The Stoic: He maintains his cool at all times.
A bear ronin who is responsible for raiding Kintaro's village in the Alternate Feudal Japan.
- Bears Are Bad News: He's a bear with a large club, and he's an antagonist in Feudal Japan. Subverted when it turns out he isn't evil by choice.
- Beary Friendly: After he is freed from Jei's control.
- Brainwashed and Crazy: Kuma is in fact brainwashed by Jei to help him capture Kintaro. Once Jei is defeated, the brainwashing is broken, and Kuma returns to being a monk at Kintaro's temple.
- Carry a Big Stick: He fights with a kanabō.
A cat whose village was raided by Jei's forces. She is a close friend of Usagi's and was Kintaro's guardian. She tasked Usagi with taking Kintaro to the Temple of the Sky Buddha when her injuries made travelling impossible for her.
- Cute Kitten: She is a benevolent cat.
- Expy: She appears to be based on Tomoe Ame from the Usagi Yojimbo comics.
- Naginatas Are Feminine: She carries a naginata but is never seen using it in battle.
- Sole Survivor: Akemi is the only survivor of Sumo Kama's attack on her village.
- Uncertain Doom: She is impersonated by Joroguma in "Osoroshi no Tabi", which suggests she had an encounter with the creature at some point. Whether this means she dead or not is unknown.
A "golden boy" pug whom Usagi and later the Turtles are charged with protecting.
- Bratty Half-Pint: Kintaro whines and complains about everything, including his protectors being "peasants", Mikey being a reptile and lacking a nose and ears, and being stuck in small spaces to hide him.
- Canon Foreigner: He was created for the series.
- The Chosen One: Born with amazing powers.
- Jerkass Has a Point: After accidentally bumping Leo in the head and breaking Jei's control over him, Kintaro is the one who realizes the Turtles are under a spell, and stops Usagi from attacking further.
- Took a Level in Kindness: By the end of the arc.
Introduced in the third season episode "The Croaking". A group of four mutant frogs and a legion of other frogs behind them. They once wanted revenge on the humans for deforestation, but have since become allies with the Turtles, particularly Napoleon with Michelangelo.
- Adaptational Villainy: Initially; the Punk Frogs from the 1987 series weren't particularly malicious or aggressive, they just happened to be trained by Shredder and were rather quick to turn on him when they realized he was using them. In this version, they had no influence from the Shredder, but are Well-Intentioned Extremists who believe Humans Are the Real Monsters, though they are still eventually convinced into a HeelFace Turn.
- Adipose Rex: Attila is very fat.
- Bamboo Technology: They bust out medieval trebuchets and battering rams made from trees and vines.
- Category Traitor: How they feel about mutants like the Turtles who befriend humans.
- Didn't See That Coming: Genghis is pretty baffled when he hears that the Turtles have befriended humans.
- Divergent Character Evolution: Napoleon, Rasputin, Attila and Genghis all have more distinct personalities and appearances than they did in the 1987 series.
- Evil Sounds Deep: Genghis, as comes with the territory when voiced by Kevin Michael Richardson.
- Fantastic Racism: None of them like humans very much. Additionally, Rasputin is mistrustful of turtles.
- Good Smoking, Evil Smoking: While there's no actual smoke seen coming from it, Attilla is constantly puffing on a hookah, an early indicator that he's a villain.
- Green Aesop: Attila wanted revenge against the humans for chipping away at his forest and killing frogs.
- HeelFace Turn: Their hearts are softened by Napoleon's friendship with Mikey, and Casey and April's heroism.
- Mooks: Unlike their 1987 counterparts, these frogs have a whole frog army behind them.
- Psycho Rangers: To the Turtles. Attila to Leonardo as The Leader, Genghis to Raphael as the brutish enforcer, Rasputin to Donatello as the Smart Guy, and Napoleon to Michelangelo as The Fool. Mike and Napoleon become friends, but the others haven't directly interacted with their counterparts.
- Shout-Out: Attila's voice suggests he just stepped out of The Godfather, and also bears a passing resemblance to Ziro the Hutt with his flamboyance and huge, sluggish physique. Napoleon is literally Napoleon Dynamite as a mutant frog, with the same actor even providing his voice. Lastly, for the frog clan as a whole, their dwelling resembles Endor.
- Reasonable Authority Figure: Once Attila gets saved by April and Casey, he admits he was wrong about humans, names Napoleon his new general and decides to work on creating a world where humans and frogs can leave together.
- Theme Naming: Like the Turtles being named after historical artists, they're named after historical conquerors.
- Villain of the Week: Until they pull a HeelFace Turn, that is.
- Weird Beard: Rasputin has a Fu Manchu-esque "beard" mad of fleshy tendrils.
The legendary cryptid who gets befriended by the Turtles while she, yes she, is stalked by an insane hunter.
- Abhorrent Admirer: Donatello gets to know what it's like having unwanted affections for a change.
- Adaptational Comic Relief: Bigfoot has occasionally cropped up during the mythos during adaptations of the farmhouse arc. In comparison to the 2003 Bigfoot-figure, however, she's mostly a joke character.
- Bigfoot, Sasquatch and Yeti: Obviously Bigfoot.
- Crossdressing Voices: She is voiced by Diedrich Bader.
- Half-Human Hybrid: Not her, but the baby she and The Finger are expecting if a tabloid from "Dinosaur Seen In Sewers" is to be believed.
- Instant Expert: Watching the Turtles with their weapons for a second is enough for her to imitate their fighting.
- Interspecies Romance: She has a crush on Donatello and later falls in love with the human who has been hunting her for years.
- Lady Looks Like a Dude: She looks and sounds like a male.
- Samus Is a Girl: Bigfoot is in fact a female creature, and falls in love with a human hunter.
- Super Strength: She can lift an entire tree with ease.
Dr. Cluckingsworth M.D.
Dr. Cluckingsworth M.D. is a mutant chicken that served as the turtle racer A.I.
- Canon Foreigner: She does not exist in the other versions.
- Full-Name Basis: As far as Mikey's concerned, the "M.D." is an integral part of her name.
- My Brain Is Big: She has an oversized brain with green veins.
- Put on a Bus: Inverted. She remains at the farm while the cast goes on the Turtle Van to New York. She makes a reappearance in "Owari" when she's present at Splinter's funeral at the farm.
- The Voiceless: She can only make clucking noises but is able to communicate with the others via a WIFI link from a laptop to an old Speak & Spell toy from Texas Instruments.
A Timestress apprenticed to Lord Simultaneous who enlists the legendary Turtles' help to defeat Savanti Romero on several occasions.
- Adaptational Badass: She's more capable of handling herself with specialized knuckles and darts in this incarnation, whereas her previous incarnations weren't quite capable of putting up a fight.
- Ascended Fangirl: In-Universe example; as she's a big fan of the Turtles who eventually become legendary throughout time and space.
- Cool Helmet: She wears a silver matte art deco helmet with luminescent blue accents.
- Future Slang: She is fond of using "grokking" as an adjective and "cold" in places where modern English speakers would use "cool."
- Love Interest: Five seconds into her first appearance, she becomes this for Mikey.
- Nice Girl: She's a very sweet, kind girl.
- Power Fist: A brass-knuckles like variety.
- Younger and Hipper: In the comics and 2003 series, she is usually depicted as a grown woman physically. Here, she's a teenage girl who is around the same age as the Turtles so she can be Mikey's love interest.
An all-powerful master of time and space, and Renet's mentor figure.
The late wife of Hamato Yoshi, and the mother of Miwa/Karai. She sought to leave Japan for New York, seeking a safer life for her baby, and believing ninjutsu to be dead. Unfortunately, fate has something terrible in store for her, as she is the driving force of a love triangle between Yoshi and Oroku Saki that changes their lives forever.
- Amicable Exes: Shen dated Saki in the past, and while they broke up, she still considered him a good friend until the end.
- But Not Too Foreign: The 2012 series showed that she's of Japanese-Chinese descent.
- This more apparent since her name is actually Chinese.
- End of an Age: Firmly believes ninjutsu is on the verge of extinction, and considering Yoshi's clan is the last organized ninja clan in the world, she's not wrong.
- Good Parents: Wanted the best life possible for her daughter.
- Happily Married: While they had their arguments, largely over their future for their child, Shen and Yoshi were truly in love and she ultimately gave her life to protect her husband.
- Love Triangle: Yoshi and Saki came to blows largely over her.
- Missing Mom: To Karai, thanks to being, you know, dead. To some extent for the Turtles as well as their would-be adoptive mother.
- Nice Girl: She was a very sweet, kind woman.
- Posthumous Character: Long dead by the time the series starts, but we get to see her alive when the Turtles are sent back in time by the Time Scepter.
- Small Role, Big Impact: She doesn't make an actual appearance until late into the third season (which is about midway through the planned series run of five seasons), but Saki's love for her and desire to take her from Yoshi is a large part of what drove him to reform the Foot Clan, attack Yoshi, and bring about all the chaos and destruction of the war between the Hamato and Foot Clan to the present day.
- Taking the Bullet: Threw herself in front of Yoshi and received a killing blow from Saki.
- Unusually Uninteresting Sight: Once the Turtles explain their benevolent intentions, she happily accepts them into her home and feeds them lunch.
- Unwitting Instigator of Doom: She is the driving force of the bitter feud between the Hamato and Foot clans, as well as contributing to Yoshi moving to New York and buying four baby turtles.
A male Salamandarian who is Mona Lisa's superior, and an experienced veteran of many fights.
- Badass Baritone: Being voiced by Keith David, this is a given.
- Borrowed Catchphrase: Once, unironically, used Michaelangelo's "Booyakasha" as a battle cry.
- Canon Foreigner: He was created for the series.
- Good Scars, Evil Scars: The left side of his face is covered in scarring and his eye that side is damaged, courtesy of Newtralizer.
- Horrible Judge of Character: See Mona Lisa's entry.
- Odd Friendship: Serious and stoic, Commander Sal gets along surprisingly well with foolish and whimsical Michaelangelo, expressing concern when the young turtle is in danger and even adopting his "Booyakasha" phrase as a battle cry on at least one occasion. Booyakasha indeed.
- Proud Warrior Race Guy: Seeks glorious combat, is very concerned with honor, and readily admits his admiration for a Worthy Opponent.
- Reasonable Authority Figure: Is more willing to work with the Hamato Clan when they run into them on the ice planet, as opposed to his lieutenant YGythgba, who is very hot-headed.
A scientist whose mind was accidentally uploaded into a robot's, who comes to Earth to seek the Turtles' help against the Triceratons at the end of season three. He is also known as the Fugitoid.
- Adaptational Badass: In the comics, the Fugitoid was a helpless fugitive being hunted down and required the Turtles to save him just as much as the 1987 April. This version is fully capable of defending himself and keeping up with the Turtles' awesomeness.
- Adaptational Villainy: Honeycutt is revealed to have sold the Heart of Darkness to the Kraang partly out of greed, whereas his past incarnations were always squeaky clean heroes. This sets him up to be The Atoner when he appears in the series.
- The Atoner: He created the black hole generator and sold it to the Kraang, him stopping the Triceratons from using it is his way of making it up for creating the thing.
- Badass Bookworm: Don't let the kind demeanor fool you, the professor is both a gifted scientist and a highly competent fighter.
- Badass Pacifist: He dislikes fighting and approaches challenges peacefully, but he's fully armed and ready for combat if the situation calls for it.
- Beware the Nice Ones: He's pleasant, likable and a self-described pacifist, but that cute little robot body is packing some serious firepower, and he will use it on you if you push him too far.
- Beware the Silly Ones: He's kind of an Absent-Minded Professor at times, but he's also a genuine battle-competent fighter.
- Big Damn Heroes: Swings in during the final minutes of season three to save the Turtles, April, and Casey from the destruction of the Earth.
- Big Good: With Splinter dead, he becomes this for the "Turtles in Space" arc that lasts the first half of season four.
- Cool Starship: His base of operations.
- Cybernetics Eat Your Soul: Professor Honeycutt fears losing his human-ness and being thought of as just a machine due to being a brain in a robot.
- Emergency Transformation: Became a cyborg after the Triceratons attacked him due to him not wanting to build weapons for them.
- Family-Unfriendly Violence: He disintegrates anyone who pushes his buttons too much.
- Famous Last Words: "Let it be known, that you are my friends, and I love you all."
- Human Aliens: He comes from a race of humanoid alien scientists looking to pierce the pinnacles of science.
- Heroic Sacrifice: The Heart of Darkness can only be destroyed through a combination of nuclear fusion and dark matter. The ship runs on dark matter and the Fugitoid runs on fusion. He goes out to save his friends and to atone for making the weapon.
- However, the last shot of the episode shows his eyes lighting up again, suggesting that he may be Not Quite Dead.
- Incorruptible Pure Pureness: He might be one of the most innocent characters in the series. This is at least how he becomes after he gains the desire to atone for his misdeeds.
- Keet: Not as much as Mikey, but he has his fair share of innocence.
- Last Episode, New Character: For season three.
- Light Is Good: He's shining silver and a noble hero.
- Losing Your Head: He gets his head cut off by debris during a Triceraton attack, but Donnie fixes him up.
- Made of Iron: Literally. He's seen taking as many hits as the Turtles, but brushes off attacks rather quickly.
- Manchild: He's the only adult on the Turtles team while they're in space, but he has his own child-like innocence.
- The Mentor: He's the only member of the team with knowledge of space and extraterrestrials and is teaching the Turtles how to adapt.
- Mr. Exposition: In season four, he provides most of the Info Dumps about the greater known universe.
- Named by the Adaptation: This version has the first name of "Zayton".
- Not Quite Dead: The final shot of Earth's Last Stand shows the lights in his eyes reactivating following his heroic sacrifice.
- Robot Buddy: Though he was originally a organic...
- Shout-Out: This would not be the first time David Tennant has played a time-traveling, eccentric genius HumanoidAlien.
- The Smart Guy: Even more so than Donnie, as his knowledge is millennia ahead.
- Technical Pacifist: He will try and reason to the very end to keep things civil amongst his friends and potential allies, but push him just a little too far and...Honeycutt: I am a pacifist, but even pacifists have to stand their ground once in a while!
- There's No Kill Like Overkill: How does the good professor dispose of his enemies? Disintegration.
- Time Travel: How he met the Turtles and plans to stop the Earth's destruction.
- Was Once a Man: He's now a man's brain in a robot body.
- The Wonka: He's really childish, but he's also a grounded scientist.
1987-Teenage Mutant Ninja Turtles
- Adaptational Dumbass: While not to the same level as their appearance in Turtles Forever, these turtles don't take things as seriously as their Darker and Edgier 2012-counterparts. They have no real sense of stealth (Leo shouting his catchphrase when their 2012 counterparts break in the rescue them, giving them away) and it doesn't occur to them that they should be inconspicuous among humans (something they were mindful of in the original show).
- Adaptational Wimp: Their ninjitsu skills are almost non-existent in this version, relying on wacky hijinks and snappy remarks to get by. Not only that, but they seem completely reluctant to use their weapons on their enemies for fear of seriously hurting them. While this seems to work when in their home dimension, they come across as complete jokes when teamed up with their 2012 counterparts or when facing 2012-Dimensional enemies like Bebop and Rocksteady.
- Blood Knight: After urging from his 2012-counterpart, Leonardo uses his swords to dispatch foot bots fairly easily, the look in his eye implying that he found the experience extremely cathartic.Leonardo: That was so... violent.
- Lighter and Softer: Compared to what they were in the series they belong to and their 2012 counterparts.
- Nonstandard Character Design: Being native to a 2-dimensional... err, dimension, the '87 Turtles are distinct enough from their 2012-counterparts not to be confused for them.Karai: Who are those goofy bug-eyed turtles?
87-Raphael: Nice to meet you too. With friends like these, who needs enemies?
- Take That!:
- Their goofy antics and reluctance to use their weapons is meant to mock the Executive Meddling done to the original series, parents complaining about the violence in their children's programming taking the show into a Denser and Wackier direction. While the show eventually ended on the Darker and Edgier "Red Sky Seasons", contemporary fans still remember it as the "goofy" version compared to other iterations of the franchise.87-Leo: Woah, woah, woah, use our weapons? But if I swing my sword at them, I could actually cut someone, and that would hurt.
2012-Raphael: So what do you use that sword for? To slice pizza?
87-Mikey: Duh. Are you guys even real ninjas?
- 87-Leo tends to shout "Turtle Power" at the drop of a hat (something that he did in the original show), something proven to at best seriously annoy his 2012-counterpart, at worst is a detriment (87-Leo accidentally ruining the 2012 turtle's attempt at stealth).
- Their goofy antics and reluctance to use their weapons is meant to mock the Executive Meddling done to the original series, parents complaining about the violence in their children's programming taking the show into a Denser and Wackier direction. While the show eventually ended on the Darker and Edgier "Red Sky Seasons", contemporary fans still remember it as the "goofy" version compared to other iterations of the franchise.
- Wrong Genre Savvy: Their home-dimension operates on Rule of Funny, so they usually solve all of their problems using shenanigans and their environment in unorthodox ways. When in the 2012-Dimension — which is slightly more realistic and much less Toon-like — they are completely out of their depth and are forced to learn (or relearn) ninjitsu.
An alien tortoise who guards the final piece of the black hole fragment.
- Adaptational Badass: Tokka was once the Shredder's immature Dumb Muscle, but this version is a giant monster guarding an Artifact of Doom.
- Adaptational Heroism: Previously, Tokka was Rahzar's partner and an enemy of the Turtles, but this incarnation is guarding a weapon from the Triceratons, and has no relationship with Rahzar, the Foot, or anyone else from Earth. Of course this version isn't a real friend of the Turtles either. Eventually, however, both she and Raphael have made good terms.
- Adaptation Species Change: From male mutant to giant female alien.
- Attack of the 50-Foot Whatever: Tokka is a kaiju sized monster.
- Decomposite Character: Her role as Rahzar's partner in the Foot Clan is given to original character Fishface.
- The Dreaded: Tokka is one of the Six Cosmic Monsters of the Universe.
- Expy: Of Gamera, even being able to fly like him.
- Gender Flip: In the previous adaptations, Tokka was a male. Here, she is a female.
- Good Parents: She is this to her son, Chompy. If traveling the cosmos to get to Earth to get him back wasn't enough, once she sees how Raph and her son have bonded together, to the point where Chompy starts crying when she initially takes him back due to being separated from Raph, she decides to let Chompy stay on Earth with Raph and the other turtles, much to their delight.
- In Name Only: The only similarities to other versions of Tokka are her name and the fact that she's a spiky turtle creature.
- Kaiju: She's enormous, so large in fact that she doesn't even notice the Turtles.
- Magma Man / Playing with Fire: She's able to breathe fire and lives in lava. She even has magma cracks on her body.
- Mama Bear: Her son is Raphael's new pet, Chompy. She comes after anyone she perceives is a danger to him.
- No-Sell: When she arrives on Earth, absolutely nothing the military throws at her has any effect at all, even with them utilizing Kraang technology.
- Super Speed: "Tokka vs. The World" reveals she can fly at speeds of 700,000,000 MPH, or half the speed of light. Fortunately she's only shown doing this in space far away from Earth.
- Turtle Power: Tokka is an alien species referred to as the Vorkathian Fire Tortoise. Whether there is only one at a time (with Chompy destined to replace her) or if the title of "Cosmic Monster" applies to all Vorkathian Fire Tortoises is unclear.
Wingnut and Screwloose
A pair of comic book superheroes Michelangelo and Casey Jones were fans of who were brought to life by the Aeon crystal.
- Expy: These incarnations of the characters are very clearly inspired by Batman and Robin of DC Comics, more specifically the incarnations in the 1966 television series.
- Heroic Sacrifice: After coming to their senses from being corrupted by the Aeon crystal that gave them life, they are perfectly willing to cease to exist so that the crystal can stop causing harm.
- Mythology Gag: While corrupted by the Aeon crystal's power, they more closely resemble how they appeared in the 1987 series and its toyline.
- With Great Power Comes Great Insanity: Realizing that the Aeon crystal is why they're real causes them to go crazy and try to use its power to wipe out everyone else.
A mutant fox who was once a child mutated by the Kraang alongside Tiger Claw, her brother. After they escaped and became hunters, at some point she betrayed him. She is the one responsible for cutting off his tail.
- Adaptational Badass: She was a fearsome warrior in the IDW continuity but a single Turtle like Leonardo or Raphael was quite capable of defeating her in combat. In this incarnation, she possesses borderline superspeed and is more than able to defeat all four Turtles in battle and even do some serious damage to heavy hitter villains like Tiger Claw.
- Adaptational Heroism: In the comics, she was an ally of the Shredder before switching to the Turtles' side. Here, she and Tiger Claw had worked together until a past incident made them enemies. Alopex is vengeful, but not villainous.
- Adaptation Dye-Job: She is a white artic fox in the comics, but an orange/brown fox in the cartoon.
- Anti-Hero / Anti-Villain: She's got it out for Tiger Claw, but she's not above using cursed weapons on him to settle the feud...or testing said weapons out on would-be-obstacles in her way, like Casey Jones.
- Arch-Enemy: Essentially is this with Tiger Claw.
- Backstab Backfire: Invokes this on Tiger Claw, who tries to shoot her after she shows mercy. She cuts off one of his arms for it.
- Cain and Abel: Alopex and Tiger Claw are brother and sister who have grudges against each other. However Alopex, despite hating him for killing their parents, spares him. Tiger Claw immediately tries to shoot her in the back.
- Composite Character: Her name is Alopex, but her design (being an orange fox instead of an arctic one and her purple ninja uniform) is based more off of Ninjara.
- Don't Make Me Destroy You: After defeating Tiger Claw, she ultimately decides to spare him because he's the only family she has left. The minute her back is turned, Tiger Claw tries to shoot her, but Alopex Flash Steps out of the way and lops off his arm, warning him that she could just as easily have killed him.
- Forced into Evil: Claims Tiger Claw made both of them enter a life of crime after their mutation.
- Good Is Not Nice: She opposes Tiger Claw, and by extension, the Foot. Don't expect her to show any mercy if you get in her way. And definitely don't try to shoot her after she shows mercy, as Tiger Claw learned to the cost of his arm.
- Male Gaze: In her debut episode, the camera focused on her rear at least three times, plus her outfit's design shows off quite a bit of her generous thighs.
- Related in the Adaptation: Alopex is Takeshi/Tiger Claw's sister.
- She's Got Legs: Assuming that her fur isn't just really thick, she's got quite a set of gams.
- Super Speed: Leo mistook her for a missile before she ran past the party wagon.
- We Used to Be Friends: With Tiger Claw; they were siblings much like Hamato Yoshi and Oroku Saki, and worked together in the circus and bounty hunter fields after their mutation. Then she betrayed him (though not without reason).
- Voiced by: Grant Moninger
The creator of Frankenstein's Monster, whom the Turtles run into on a time traveling adventure.
- Adaptational Heroism: In the original novel, Dr. Frankenstein adamantly refused to see any good in the creature and never tried to form a paternal bond with it. Here, he's quickly willing to apologize for calling him an abomination and even outright calls him his son.
- Voiced by: Hoon Lee
The leader of the Hamato Clan and Splinter/Hamato Yoshi's late father.