Chester Morris

Character: Dr. Carlo Lombardi

Marla English

Character: Andrea Talbott / Elizabeth Wetherby

Tom Conway

Character: Timothy Chappel

Cathy Downs

Character: Dorothy Chappel

Lance Fuller

Character: Dr. Ted Erickson

Ron Randell

Character: Police Lt. Ed James

Frieda Inescort

Character: Mrs. Chappel

Frank Jenks

Character: Plainclothes Sgt. with Lt James

El Brendel

Character: Olaf, the butler

Paul Dubov

Character: Johnny, the barker

William Hudson

Character: Bob, the ex-fiancé

Flo Bert

Character: Marta, the Maid

Jeanne Evans

Character: Mrs. Brown

Kenneth MacDonald

Character: Police Doctor with Prof. Anderson

Jack Mulhall

Character: Lombardi's Lawyer

Edward Earle

Character: Professor Anderson

Bess Flowers

Character: Party Guest

Paul Blaisdell

Character: The She-Creature

Spike

Character: King the Dog