Actor
Cry Uncle!
1971
as Angry Man in Parking Lot (uncredited)
Documentaries
Reflections of 'The Dark Crystal'
2007
as Himself
Of Muppets & Men
1981
as Self
Directing
Martians Go Home
1990
Director
The Yattering And Jack
1987
Director
Production
Fiend of Dope Island
1961
Producer
Writing
The Very Best of the Muppet Show: Volume 3
2001
Writer
The Very Best of the Muppet Show
1999
Writer
The Very Best of the Muppet Show: Volume 2
1999
Writer
Masters of the Universe
1987
Screenplay
Gonzo Presents Muppet Weird Stuff
1985
Writer
Supergirl
1984
Screenplay
Nate and Hayes
1983
Writer
The Dark Crystal
1982
Screenplay
Running Scared
1980
Screenplay
Fore Play
1975
Writer
Between Time and Timbuktu
1972
Writer
Dealing: Or the Berkeley-to-Boston Forty-Brick Lost-Bag Blues
1972
Writer
Cry Uncle!
1971
Screenplay