"Milquetoast Henry Limpet experiences his fondest wish and is transformed into a fish. As a talking fish he assists the US Navy in hunting German submarines during World War II."
Don Knotts
as Henry Limpet
Carole Cook
as Bessie Limpet
Jack Weston
as George Stickel
Andrew Duggan
as Harlock
Larry Keating
as Admiral P.P. Spewter
Oscar Beregi Jr.
as Nazi Admiral (as Oscar Beregi)
Charles Meredith
as Fleet Admiral
Elizabeth MacRae
as Ladyfish (voice)
Paul Frees
as Crusty (voice)
Wesley Gale
as Man Staring Into Window (uncredited)
Leon Alton
as Officer at Fleet Admiral's Meeting (uncredited)
Phil Arnold
as Short Fisherman (uncredited)
George Bruggeman
as Nazi Officer (uncredited)
Paul Busch
as Sonar Man (uncredited)
Al Checco
as Sailor (uncredited)
Cordy Clark
as Giggling Girl (uncredited)
Roydon Clark
Sayre Dearing
as Passerby/Naval Officer at Meeting (uncredited)
George DeNormand
Dan Dowling
as Naval Officer at Meeting (uncredited)
Harold Dyrenforth
as U-Boat Captain (uncredited)
Louie Elias
Lisabeth Field
as Miss Barnes (uncredited)
Logan Field
as Lieutenant (uncredited)
Fred Fisher
Walter Friedel
George Golden
as Naval Officer at Fleet Admiral Meeting (uncredited)
Marv Goux
John Hale
Sam Harris
as Officer at Fleet Admiral's Briefing (uncredited)
George Holmes
as Scientist (uncredited)
Joseph La Cava
Mike Lally
Harold Miller
Charles Morton
as Boat Captain (uncredited)
Henry Norell
Jack Pepper
as Sport Fishmern (uncredited)
Montie Plyler
as Helmsman (uncredited)
Felix Reinsch
as Submarine Captain (uncredited)
Waclaw Rekwart
as Passerby (uncredited)
Heinz Sadler
Scott Seaton
as Old Man in Shipping Office (uncredited)
Jack Shea
John Truax
as Policeman (uncredited)
Edward Wermel
Feridun Çölgeçen
Peter Adams
Jameson Brewer
Screenplay
Joe DiMona
Adaptation
Arthur Lubin
Director
John C. Rose
Theodore Pratt
Novel
Bill Tytla
Animation Director
Donald Tait
Editor
Bill Phillips
Makeup Artist
Sergei Petschnikoff
Assistant Director
Ira Stewart
Hawley Pratt
Jean Burt Reilly
Hairstylist
Lenore Weaver
Harold E. Stine
Director of Photography
Stanley Jones
Sound
William L. Kuehl
Set Decoration
Gerry Chiniquy
Producer
Louis Phillips
Edmond F. Bernoudy
John W. Dunn
Story Supervisor
Robert McKimson
LeRoy Deane
Art Direction
Gordon Bau
Makeup Supervisor
Frank Perkins
Music
Paul Burnett
Gaffer