
Ivan Reitman OC (October 27, 1946 – February 12, 2022) was a Canadian-American film and television director, producer and screenwriter. He was best known for his comedy work, especially in the 1980s and 1990s. He was the owner of The Montecito Picture Company, founded in 1998.
Notable films he directed include Meatballs (1979), Stripes (1981), Ghostbusters (1984), Ghostbusters II (1989), Twins (1988), Kindergarten Cop (1990), Dave (1993), and Junior (1994). Reitman also served as producer for such films as Animal House (1978), Beethoven (1992), Space Jam (1996), and Private Parts (1997).
Description above from the Wikipedia article Ivan Reitman, licensed under CC-BY-SA, full list of contributors on Wikipedia.

Ghostbusters
1984 · as Zuul / Slimer (voice) (uncredited)

Ghostbusters II
1989 · as Man Walking Outside Firehouse / Slimer (voice) (uncredited)

Hotel for Dogs
2009 · as Self - Closing Credits Sequence (uncredited)

Ghostheads
2016 · as Self

Drunk Stoned Brilliant Dead
2015 · as Self - Director

On the Scene with the Ghostbusters
1984

Cleanin' Up the Town: Remembering Ghostbusters
2020 · as Self

Ghostbusters 1999
1999 · as Self

Belushi
2020 · as Self (archive footage)

Arnold Schwarzenegger: Hollywood Hero
1999 · as Self

The Yearbook: An Animal House Reunion
1998 · as Self - Producer

Who You Gonna Call?
2020 · as Self

Animal House: The Inside Story
2008 · as Self

The Canadian Conspiracy
1986 · as Self

Fantastic Mr. Murray
2019 · as Self - Interviewee (archive footage)

A Home for Everyone: The Making of 'Hotel for Dogs'
2009 · as Self

Imagining 'Heavy Metal'
1999 · as Self

Old School: Orientation
2003 · as Himself