Otto Kruger

Character: Dr. Stendahl

Vicky Lane

Character: Paula Dupree - the Ape Woman

Amelita Ward

Character: Ann Forrester

Phil Brown

Character: Don Young

Jerome Cowan

Character: Detective W.L. Harrigan

Rondo Hatton

Character: Moloch the Brute

Eddie Acuff

Character: Bill

Ernie Adams

Character: Jim

Charles Wagenheim

Character: Fred

Eddy Chandler

Character: Motorcycle Cop

Jack Overman

Character: Detective - George

Pat Gleason

Character: Tom - Second Morgue Attendant (uncredited)

William Murphy

Character: Johnny - Errand Boy (uncredited)

Bob Pepper

Character: Policeman at Morgue (uncredited)