"The discovery of a perfectly preserved caveman prompts a mad scientist to attempt a daring brain transplant."
Bela Lugosi
as Prof. Dexter
John Carradine
as Prof. John Gilmore
Frank Moran
as Ape Man
Teala Loring
as Anne Gilmore
Tod Andrews
as Steve Rogers
Mary Currier
as Hilda Gilmore
Ernie Adams
as Tramp, Willie the Weasel
Eddy Chandler
as Sergeant
George Zucco
Mike Donovan
as Policeman Barney (uncredited)
George Eldredge
as Policeman (uncredited)
Horace B. Carpenter
as Theater Watchman (uncredited)
Sam Katzman
Producer
Robert Charles
Screenplay
Jack Dietz
Phil Rosen
Director
Glen Glenn
Sound Engineer
Dave Milton
Set Designer
Marcel Le Picard
Director of Photography
Edward J. Kay
Music Director
Barney A. Sarecky
Associate Producer
Ray Mercer
Special Effects
Arthur Hammond
Assistant Director
Carl Pierson
Editor
