Michael Bell

as Opus the Penguin (voice)

Joe Alaskey

as Truffles / The Ducks (voice)

John Byner

as Bill (voice)

Tress MacNeille

as Chicken (voice)

Alexaundria Simmons

as Ronald-Ann (voice)

Andrew Hill Newman

as Milquetoast (voice)

Robin Williams

as Kiwi (voice) (credited as Sudy Nim)