Here are some deleted scenes from Ghostbusters II along with script excerpts of the scenes. The written scenes below were taken from the final shooting script. What is written may vary from what is spoken by the actors. In some cases the scene still appears in the film, but I have some still photos of shots that were not used. In other cases, footage from the scene was used in the film in a completely different way (such as during the end credits). The list of scenes below is in order of how they would have appeared in the movie. Following that are some odds and ends that aren't full scenes, but were deleted from the film nonetheless.
The frog ghost, which would have hopped into view following the ghost train's disappearance, displaying needle-like fangs and a long probing tongue. The January 1990 issue of Cinefantastique magazine says it was "axed when the live-action subway footage didn't work". The book "Ghostbusters: The Ultimate Visual History" by Daniel Wallace, and another source, both say that it was edited out because Ivan Reitman didn't think it was scary enough.
The montage "scene" of Louis discovering Slimer eating lunch was originally a tad longer. After Louis falls over the couch (and Slimer presumably flies away), Janine runs down the stairs holding a pot of coffee, sees Louis on the floor behind the couch, and comments, "Oh, Louis. You're such a cut-up." (This black and white image came from a workprint video that was uploaded by William Forsche to Facebook and YouTube.)