The producers didn't like what director Harold Daniels had done with the film, so they hired Jerry Warren to come in and finish it. Reginald Le Borg also directed some scenes, uncredited.
John Carradine completed his scenes in the fall of 1965, then rushed off to Iowa to shoot The Hostage (1967).
Although they play brothers, legendary horror stars Lon Chaney Jr. and John Carradine appear together in no scene in this film.
Lon Chaney Jr.'s character sports small goat horns on his forehead, perhaps the only reason for one of this movie's alternate titles, "Blood of the Man Devil." Another alternate title for the film was that of Lora Crozetti's original story on which it is based, "The Widderburn Horror."
Final film of Sabrina.