Stay Puft Marshmallow Man

Stay Puft debuted in Pooh's Adventures of Ghostbusters. When Pooh and the others faced Gozer, they have to choose a form for him. Noone thought except Ray Stanz. He chose a form that is harmless, something he loved as a kid, something that won't destroy them. He chose Stay Puft. The Ghostbusters destroyed him. But, Stay Puft returned at the end.

SPOILERS:

Stay Puft returned not for vengence, but to be pals w/ Pooh and pals.