In 1986 Kenner produced and sold the original two ghosts we would come to love from Ghostbusters, Green Ghost and the Stay-Puft Marshmallow Man. When it came to listing them on the card back after the first series hero figures we know who Kenner loved more.
This happy Stay-Puft came about after The (Real) Ghostbusters defeated Gozer. It isn’t explained how melted marshmallow “rematerialized” and ended up as a whole marshmallow man. In The Real Ghostbusters Mr. Stay-Puft lived in the ectocontainment unit, was friends with Slimer, and helped The Real Ghostbusters when he was needed. The friendly, popular Stay-Puft was seen 13 times throughout the series run!
It would have been great if some sort of scale could have been determined to make Stay Puft (and Green Ghost) more to size with The Real Ghostbusters. Within a year Kenner did come out with a Stay-Puft Marshmallow Man plushie. They told kids to use it to battle The Real Ghostbusters.