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)

Dub Taylor

Digger (voice)

John Fiedler

Owl (voice)

Robie Lester

Miss Bianca (singing voice, uncredited)

Peter Renaday

American Deligate (voice) (uncredited)