As in the Steve Jackson "RPG" 'Toon' ?? I played this quite a bit when I was a kid. fun stuff. My main character was a little green four-legged frog with a super-stretchy prehensile tongue of near-infinite length, his name was 'Rogger Ribbit' (doh!). His biggest accomplishment was when he fell off a cliff, pulled a stop sign out of his pocket (you can pull any sort of sign out of your Back Pocket (TM) at any time, so says the book), rolled a successful 'fast talk' roll, and convincing the ground to STOP!!!! It was so fun to play a game with no rules, just like 'Calvinball' in many ways.
How is this game you mention played?