The movie Ghostbusters ruled theaters in the summer of 1984 …that's almost 30 years ago! Uproxx has a collection of photographs taken on the set that show the cast out of character and a peek at the special effects. Here you see the ghost they called the Onionhead Ghost, who later became known as Slimer, being worn by a guy in black velvet pants. You'll also see Sigourney Weaver levitating and the guy in the Stay Puft Marshmallow Man costume, among other treats.