"A university chemistry professor experiments with an ancient Mayan gas on a medical student, turning the would-be surgeon into a murdering ghoul as part of a plan to steal his lover."
George Zucco
as Dr. Alfred Morris
David Bruce
as Ted Allison
Evelyn Ankers
as Isabel Lewis
Turhan Bey
as Eric Iverson
Robert Armstrong
as 'Scoop' McClure
Milburn Stone
as Sgt. Macklin
Addison Richards
as Editor Gavigan
Rose Hobart
as Della Elliott, reporter
Andrew Tombes
as Mortician Eagan
Charles McGraw
as Detective Garrity
Lillian Cornell
as Isabel's Singing Voice (voice) (uncredited)
Gus Glassmire
as 1st Cemetery Caretaker
Gene O'Donnell
as Radio Reporter (uncredited)
Mike Lally
as Reporter (uncredited)
Chuck Hamilton
as Policeman (uncredited)
Hans Herbert
as Attendant (uncredited)
Isabel La Mal
as Maid (uncredited)
Bess Flowers
as Woman in Audience (uncredited)
Cyril Ring
as Man in Audience (uncredited)
Bert Moorhouse
Edmund Mortimer
Lew Kelly
as Stagehand (uncredited)
William Ruhl
Jack Pierce
Makeup Artist
Brenda Weisberg
Screenplay
James P. Hogan
Director
Paul Gangelin
Russell A. Gausman
Set Decoration
Milton Carruth
Editor
Hans Kraly
Original Story
Bernard B. Brown
Sound Director
Hans J. Salter
Music Director
Martin Obzina
Art Direction
Ben Pivar
Associate Producer
A.J. Gilmore
John B. Goodman
Milton Krasner
Director of Photography
Vera West
Costume Designer