dan aykroyd conceived of the stay puft marshmallow man for his initial script for "ghostbusters" the movie. he created the character to show that "it seems harmless and puffy and cute—but given the right circumstances, everything can be turned black and become evil". stay puft was only one of many large-scale monsters in this early draft of the script, but after aykroyd worked with co-writer harold ramis and director ivan reitman, the team scaled back the intended sequence until only stay puft remained out of the original large-scale monsters.