An Pencil and paper RPG from Palladium Books
, that seems to constantly be changing states between in and out of print.
Taken from their website:
The classic super-hero role-playing game of mutant animals and the (serious) Ninja Turtles. Nearly 200,000 copies sold!
Don't think this is a game for little kids. The TMNT role playing game offers over a 100 different mutant animals and a ton of cool ideas for super-hero gaming. And many of the TMNT books can be used to create mutants, aliens and D-bee characters for Rifts®, Heroes Unlimited, Robotech® II: The Sentinels, and even Ninjas & Superspies or Nightbane.