- Country: USA
- Genres: Drama, Horror, Mystery
- Release: 1942-11-27
- Director: John Brahm
- Writers: Lillie Hayward , Michael Jacoby , Jessie Douglas Kerruish
- Language: English
- Stars: James Ellison , Heather Angel , John Howard , Bramwell Fletcher , Heather Thatcher , Aubrey Mather , Halliwell Hobbes (1877–1962) , Matthew Boulton , Harry Carter , Alec Craig
- Runtime: 63 min
- Awards: N/A
- AKA: O Segredo do Monstro (Brazil) , Бессмертный монстр , The Undying Monster , Le Secret du Monstre (Canada) , The Undying Monster (Canada) , El secreto del monstruo (Argentina) , The Hammond Mystery (United Kingdom) , Das unsterbliche Monster (Germany) , To teras pou den pethainei (Greece) , El secreto del monstruo (Mexico) , O Segredo do Monstro (Portugal, Portuguese Republic) , The Undying Monster (United States of America)
- Plot: A werewolf prowls around at night but only kills certain members of one family. It seems like just a coincidence but the investigating Inspector soon finds out that this tradition has gone on for generations and tries to find a link between the werewolf and the family, leading to a frightening conclusion.
- IMDB:tt0035489
The Undying Monster Cast · · · ALL
John Brahm
Director
James Ellison
Robert Curtis
Heather Angel
Helga Hammond
John Howard
Oliver Hammond
Bramwell Fletcher
Dr. Jeff Colbert
Heather Thatcher
Conita 'Christy' Christopher
Aubrey Mather
Inspector Craig
Halliwell Hobbes
(1877–1962)
Walton the Butler
Matthew Boulton
Coroner (uncredited)
Harry Carter
Warren (uncredited)
Alec Craig
Will the Groundsman (uncredited)
Douglas Gerrard
Jury Foreman (uncredited)
Holmes Herbert
Chief Constable (uncredited)
Eily Malyon
(1879–1961)
Mrs. Walton (uncredited)
Charles McGraw
Strud Strudwick (uncredited)
Clive Morgan
Foster (uncredited)
John Rogers
Tom Clagpool (uncredited)
Jerry Sheldon
Villager (uncredited)
Donald Stuart
Charlie Clagpool (uncredited)
David Thursby
Inspector Craig's Assistant (uncredited)
Valerie Traxler
Kate O'Malley (uncredited)
Heather Wilde
Millie the New Maid (uncredited)