Like many other 1980s cartoon shows, Teenage Mutant Ninja Turtles was intended primarily as a vehicle to sell toys. Fortunately, as was the case with all the most successful of these franchises, the writers took their job more seriously than that and actually tried to craft entertaining stories around the restrictions and requirements imposed on them by Playmates. Most stories centered around the core group of main characters, the four Turtles themselves, Splinter, April O'Neil, Krang, Shredder, Rocksteady and Bebop, and a handful of supporting cast members (like April's coworkers Vernon Fenwick and Irma Langinstein) who were never released as toys despite their exposure on the show. Another handful of characters, like Baxter Stockman or Casey Jones, were regularly recurring stars appearing in a dozen or so episodes, leaving us eagerly awaiting their next guest appearance.
Of course, Playmates wanted to sell more toys than that, so occasionally an episode would have to feature another character so the kids at home would know he exists. The introduction would need to provide some degree of backstory for the character and demonstrate his powers and abilities in a flattering way. If it was a good guy, he'd save the Turtles from that episode's evil plot. If it was a bad guy, he'd kick the Turtles around for two commercial breaks until they found some way to outsmart him or turn his powers against him. A surprising amount of the time, the good guy characters would begin the episode as a bad guy and have a sudden attack of conscience or a realization that the bad guys had tricked him, which would bring him to the side of good in the end.
Many of these characters only had one or two episodes of exposure. Certain other toys, like Ace Duck, never had an episode featuring them at all. One suspects that parents, who weren't watching the show, didn't know this and would buy Ace Duck as a birthday present on the basis of the TMNT logo on the package. Still other characters, mostly one-episode villains, were never released as toys.
So here's to all the "other" characters in Teenage Mutant Ninja Turtles, who never got the exposure, character development, or popularity they needed to become fan favorites, but were still released as toys:
Second String Heroes
- Mondo Gecko:
- Only appearing in two episodes, Mondo Gecko was pure wasted potential. A bit of revisionist history revealed that a gecko lizard was caught in the same mutagen spill that created the Turtles, but the gecko was picked up and taken away by a criminal who raised him into a life of crime. Mondo Gecko was a skateboarder and an excellent fighter, beating up Michaelangelo twice in his first appearance, but later rehabilitated through hypnosis. Unfortunately, the writers completely ignored the fact that he was a gecko, and thus should have been able to scale sheer walls and crawl across ceilings.
- The Neutrinos:
- Dask, Zak and Kala. Alien teenagers from Dimension X who talked in 1950s slang and rode a couple of flying cars modeled after classic convertibles. Their major contribution to the show was the flying cars.
- The Punk Frogs:
- Genghis Frog, Napoleon Bonafrog, Rasputin the Mad Frog, and Attila the Frog. I have no idea why they're called the punk frogs, since "punk" is the last word you'd think to see them. Created when a shipment of mutagen accidentally wound up in a Florida swamp (despite their Louisiana accents), the frogs (not being trained fighters) were pretty worthless and had limited exposure in the cartoon. All they could really do was jump and swim.
- Usagi Yojimbo:
- Samurai rabbit from a parallel dimension where anthropomorphic animals are the dominant life form, Usagi was a guest star from his own comic series and he is covered more in depth in his own writeup. Raphael said it best: He's not only from medieval Japan, but also from an alternate universe. So naturally, he speaks English. Usagi was an excellent swordsman, easily Leonardo's equal and able to defeat the other Turtles in one-on-one combat.
- Zach, the Fifth Turtle:
- Neither a turtle nor an actual member of the team (despite his homemade turtle costume), Zach was a normal human boy with a severe case of hero worship for the Turtles. Essentially a replacement hostage for April O'Neil, Zach was occasionally of some use as a spy since April, being a TV personality, was too publicly known and the Turtles couldn't pass for humans.
- Mutagen Man, Mona Lisa, Muckman:
- One-shot heroes that never had a chance to shine. Mutagen Man was created when he fell into a vat of mutagen, and now requires a special suit that feeds him a constant supply of mutagen to survive. He has the power to temporarily transform himself to copy the shape of anyone he sees. Mona Lisa was some kind of nondescript lizard and little more than a generic tough hero grrl. Muckman was a former garbage man who was mutated into a grotesque trash monster that emitted some kind of mutagenic radiation that weakened mutants who got too close to him. None of them appeared in more than one episode.
Second String Villains
- Created with the Punk Frogs as their main adversary, Leatherhead was a huge mutant alligator with a Cajun accent. He was incredibly strong and tough but otherwise uninteresting. I blame the Frogs for that, you're only as good as your opponent. Leatherhead had no connection to Shredder and Krang outside the fact that they were responsible for his mutation. Leatherhead is rumored to be a more interesting character in the new cartoon, with a backstory taken from the 1980s Mondo Gecko, who does not appear in the new cartoon.
- Robot ninja turtle created by Krang to fight the Turtles, he was reprogrammed by Donatello as a good guy by the end of the episode. Had sort of a multiple personality disorder because he was programmed with a brain scan of all the turtles, and switched personalities along with weapons and fighting styles. The Turtles eventually beat him by trading weapons with each other, confusing him as to what fighting style he should use to defeat them. Occasionally seen as a level boss in the video games.
- The Rat King:
- Really more of an independent operator, The Rat King had the power to communicate with and command swarms of rats. He sought to conquer the sewers (low, but still unrealistic ambitions) and came into conflict with the Turtles and, once, Leatherhead for domination New York's filth. The Rat King got more exposure than any other villains on this list.
- Accidentally created when Rocksteady and Bebop exposed their pet baby turtle to a canister of super-mutagen, Slash was an uncontrollable super-powerful mutant who just wanted his Binky back. His Binky was a small plastic palm tree from his aquarium, and his only material possession. He tore up New York to get it back, and was eventually stopped when the turtles tricked him and launched him into space on a rocket. Later, an alien race discovered him and, taking pity on his child-like intelligence, increased his IQ to super-genius level and sent him back to Earth. Now both hyper-intelligent and super strong, he was unstoppable until a blow to the head reverted him back to normal.
- General Traag:
- Commander of the rock warriors, Krang's army in Dimension X, General Traag was unfailingly loyal to Krang with apparently a long history of distinguished service. Like all the rock warriors, his body was covered in stone armor, or perhaps made of stone, making him very difficult to damage. The rock army had access to powerful, high tech weapons and spaceships, and were waiting for their chance to invade Earth... just as soon as Krang scraped together enough power to open a dimensional warp gate big enough.
- Wingnut and Screwloose:
- One-shot villains in a single episode, they were aliens, not mutants, who were using a military school as a base to take over the world with a mind control device. Wingnut looked like a vampire bat and Screwloose a mosquito. I wouldn't mention them except that they were released in toy form.