Slimer, originally referred to as "Onionhead" and sometimes "the Mean Green Ghost", is a character from the Ghostbusters franchise. He appears in the films Ghostbusters (1984), Ghostbusters II (1989), and the remake Ghostbusters (2016), in the animated television series: The Real Ghostbusters, Slimer! and Extreme Ghostbusters, and in the video games: Ghostbusters: The Video Game (2009), Beeline's Ghostbusters (2013) and Ghostbusters: Spirits Unleashed (2022). Slimer was voiced by Ivan Reitman and Adam Ray in the films and by Frank Welker in the animated series. In The Real Ghostbusters, he is the Ghostbusters' mascot and friend (unlike the films, where he is a ghost who needs to be busted).