The Non-stop Mutating Monster!
Victim of Krang's insidious experiments, Seymour Gutz woke up from a lab table only to find himself hideously transformed into Mutagen Man - a pathetic, dripping, ever-changing mutating monster. Confined to a mechanical life support system that holds his mutating body together, Mutagen Man is now dependent on Ooze to replenish his deteriorating form. Forced to do Shredder's bidding in exchange for Retromutagen Ooze, Mutagen Man reluctantly performs dastardly deeds to get the substance his body so desperately craves.
Armed with his Mutagen Machine Gun, Mutagen Man relentlessly tracks down the Turtles and their allies. Head for the sewers and hide your Ooze! Mutagen Man's on his way - and you just know he has the guts to get you!
- Mutagen Man was based on a sketch made by Peter Laird for Playmates Toys, Laird originally called it "The Unknown" and would be a mutant crossing between an ape and some kind of insect that went wrong.
- He was listed as one of the villains, despite in the cartoon he became an ally to the Turtles.