Bob Newhart
Bernard (voice)
Eva Gabor
Miss Bianca (voice)
Geraldine Page
Madame Medusa (voice)
Joe Flynn
Mr. Snoops (voice)
Jeanette Nolan
Ellie Mae (voice)
Pat Buttram
Luke (voice)
Jim Jordan
Orville (voice)
John McIntire
Rufus (voice)
Michelle Stacy
Penny (voice)
Bernard Fox
The Chairman (voice)
Larry Clemmons
Gramps (voice)
James MacDonald
Evinrude / Brutus / Nero (voice)
George Lindsey
Rabbit (voice)
Bill McMillian
TV Announcer (voice)
Dub Taylor
Digger (voice)
John Fiedler
Owl (voice)
Robie Lester
Miss Bianca (singing voice, uncredited)
Mel Blanc
Bats (voice) (uncredited)
Peter Renaday
American Deligate (voice) (uncredited)