Ashley Johnson

Peter Shepherd (voice)

William Sanderson

Professor J.S. Ibsen (voice)

Pamela Adlon

Rock (voice)

Debi Derryberry

Judy Shepherd (voice)

Sherman Howard

Van Pelt (voice)

Melanie Chartoff

Aunt Nora Shepherd (voice)

Bill Fagerbakke

Alan Parrish (voice)

Billy West

(voice)

Tim Curry

Trader Slick (voice)

Kevin Schon

Dead-Eye (voice)