This is Teenage Mutant Ninja Turtles and Other Strangeness, from 1985, an RPG built for Palladium’s house system (in other words, compatible with Rifts) and based on Eastman and Laird’s 1984 indie comic.

I should stress that this is based on the comic for a couple reasons. It took a little while for the comic to build up word of mouth, but Palladium licensed it for an RPG pretty much immediately. The thing was an enormous success for Palladium for a while. So much so that, while licensing Robotech, the company used TMNT as an example of what they could do and the Robotech people were so impressed by the property that they picked TMNT up for a cartoon. Ironically, that cartoon, which jettisoned the comic’s grim and gritty atmosphere in favor of more kid-friendly fare, kind of killed the RPG – the cartoon evaporated the cool factor for teens who had been playing the game.

TMNT, and its spin-off, After the Bomb, are my favorite Palladium lines. They  shook me out of my largely D&D-centric world and illustrated how odd RPGs could be. The game’s legacy is probably the mutation rules, which are robust and easy to apply to make your favorite animal a badass.