Trivia: The sound of Vigo growling is exactly the same growl that the terror dogs from the first Ghostbusters make.
Trivia: When Ray and Egon see Vigo's name on the "Occult Reference Net," his last name is the same as the twin actors who play Oscar.
Trivia: Slimer had no name in the first Ghostbusters movie, but the producers nicknamed him "onionhead" because of his awful smell. He was named Slimer in the cartoon series "The Real Ghostbusters." The name came from the scene in Ghostbusters where Ray shows Winston the containment unit and says, "This is where we store all the vapors and entities and slimers we trap." Since Venkman was slimed in the hotel, they decided to name the ghost that did it Slimer.
Trivia: Oscar is actually played by twins, Hank and Will Deutschendorf. These boys are the nephews of the late singer John Denver (formerly Deutschendorf). The boys are John's brother Ron's children. Tragically, Hank passed away in 2017, after a prolonged battle with schizoaffective disorder - a serious mental-health illness he had been struggling with for years.
Trivia: The original theatrical version ended with Slimer eating the camera, just like in the first Ghostbusters film. This has been removed for the video releases.
Suggested correction: This is a popular rumor, and some people claim to remember it, but there's no supporting evidence or footage to confirm this. In fact, after doing some research, I came across an article where a projectionist screened an original 1989 35mm print of the film to see if it did indeed end with this mythical Slimer scene... and the print contained no such scene, ending the exact same way as the home video releases. Sadly, this appears to simply be another instance of the dreaded "Mandela Effect," where people remember something that didn't really happen/wasn't real. Furthermore, if they actually had spent the time and money creating an effect like that, what purpose would there be to cutting it from home video releases? Effect like the ones in this film were harder and more laborious to make in the 1980's. They wouldn't just cut effects out for no reason.
Trivia: When the ghostbusters go to see the picture of Vigo in the museum, Ray becomes entranced by looking at the eyes. Winston asks him if he is OK. Look at what Winston is holding. It's some form of ghostbusting gadget made out of a potato masher.
Trivia: The film was partially informed by the popular cartoon series "The Real Ghostbusters." In particular was the inclusion of "Slimer" (who was made into a popular character on the series) and Janine's "look", which was heavily inspired by the series.
Trivia: To date, this is the only Ghostbusters movie (out of 5) where there is no appearance of any living Staypuff marshmallow men.
Trivia: The first draft of the script involved Dana being kidnapped and taken to Scotland, where she'd discover an underground world of fairy-tale creatures, fairies, monsters and witches. The Ghostbusters would then have to travel to Scotland to save her. Dan Aykroyd has said that the script was simply "really too far out... too inaccessible."
Trivia: A great deal of the film was changed after poor test-screenings. In the original cut, there's a scene where Ray is possessed by Vigo earlier in the film and dangerously drives the Ecto-1 through the streets. Eugene Levy also appeared as Louis' cousin who helps the Ghostbusters get out of the hospital. There was a sub-plot of Louis trying to catch Slimer but being comically out-witted every time. Several scenes were substantially longer. And the entire climax was completely different.
Trivia: On the theater marquee, the film "Cannibal Girls" (with Eugene Levy and Andrea Martin) is seen. "Cannibal Girls" was directed by "Ghostbusters" and "Ghostbusters 2" director, Ivan Reitman.