#4. The original treatment was much more epic.

The original 40-page draft called for the film to take place in the future, where dozens of groups of Ghostbusters fought specters across time and space.

The iconic Stay-Puft Marshmallow Man showed up on page 20, and was just one of 50 giant monsters the ‘Busters would have to destroy to save civilization.

Photo Credit: Ghostbusters: The Ultimate Visual History

Director Ivan Reitman estimated that it would have cost $300 million to make that version of the film, so he suggested they focus on one group of men getting their start in the ghost fighting business.

The Marshmallow Man was now ready for his close-up.

#5. Sigourney Weaver really wanted the part.

Photo Credit: GIPHY

Before Ghostbusters, Weaver was known mostly for her role as Ripley in 1979’s Alien, but she really wanted to land in a comedy.

At her audition, Ripley, or rather Ms. Weaver, chose to do a wordless scene where she turned into one of Gozer’s hell-hounds. She slithered around on the couch and snarled at Reitman, who was super-impressed. Obvs.

Find out how they filmed that scene where Dana floated over the bed after the jump!