 
                                                                107 minutos
A timid, nearsighted chemistry teacher discovers a magical potion that can transform him into a suave and handsome Romeo. The Jekyll and Hyde game works well enough until the concoction starts to wear off at the most embarrassing times.
 
                                                        Jerry Lewis
Professor Julius F. Kelp / Buddy Love / Baby Kelp
 
                                                        Stella Stevens
Stella Purdy
 
                                                        Del Moore
Dr. Hamius R. Warfield
 
                                                        Henry Gibson
Gibson, College Student
 
                                                        Kathleen Freeman
Millie Lemmon
 
                                                        Richard Kiel
Man in Gym (uncredited)
 
                                                        Norman Alden
Football Player
 
                                                        Howard Morris
Mr. Elmer Kelp
 
                                                        Elvia Allman
Edwina Kelp
 
                                                        Milton Frome
Dr. M. Sheppard Leevee
 
                                                        Doodles Weaver
Rube
 
                                                        Murray Alper
Gym Attendant (uncredited)
 
                                                        Buddy Lester
Bartender
 
                                                        Med Flory
Football Player
 
                                                        Seymour Cassel
Bored Man
 
                                                        Stephanie Hill
Waitress (uncredited)
 
                                                        Marvin Kaplan
English Student
 
                                                        Skip Ward
Football Player
 
                                                        Billy Bletcher
Plumber (uncredited)
 
                                                        Robert Donner
College Student (uncredited)
 
                                                        Art Gilmore
Narrator (voice) (uncredited)