On screen
Cast
34 credited performers
Jonathan David Cook
Big Guy (voice)
Pamela Adlon
Rusty (voice)
Jim Hanks
Dwayne Hunter (voice)
Gabrielle Carteris
Dr. Erika Slate (voice)
Stephen Root
Dr. Donovan (voice)
Kathy Kinney
Jenny (voice)
Kevin Michael Richardson
Garth (voice)
M. Emmet Walsh
Mack (voice)
R. Lee Ermey
General Thornton (voice)
Clancy Brown
Character not listed
Dee Bradley Baker
Character not listed
Dean Haglund
Character not listed
Maurice LaMarche
Character not listed
Ron Perlman
Character not listed
Tim Curry
Dr. Neugog (voice)
Cam Clarke
Character not listed
Mary Kay Bergman
Character not listed
Jim Piddock
Character not listed
Jillian Warry Barberie
Character not listed
Maura Tierney
Character not listed
Jeremy Suarez
Character not listed
Nicholas Guest
Character not listed
Nick Jameson
Character not listed
Nora Dunn
Character not listed
Patrick Pinney
Character not listed
Artwork unavailable
Justin Jon Ross
Character not listed
Jennifer Hale
Character not listed
Artwork unavailable
John Garry
Character not listed
John de Lancie
Character not listed
Kevin Schon
Character not listed
Michael Chiklis
Character not listed
Artwork unavailable
Helen Kalafatic
Character not listed
Brian Doyle-Murray
Character not listed
Stan Freberg
Character not listed