The Stay-Puft Marshmallow Man is a fictional character from the Ghostbusters franchise. He first appears in the 1984 Ghostbusters film as a logo on a bag of marshmallows in Dana Barrett's apartment, on an advertisement on a building near the Ghostbusters' headquarters.
See also: See Tickets, The Rebel Flesh, The Eleventh Hour (Doctor Who), List of Jurassic Park characters, AMA Supercross Championship, and The Hitchhiker's Guide to the Galaxy.