The producers did not 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 film in the fall of 1965, then rushed off to Iowa to shoot The Hostage (1967).
Although they play brothers in this film, legendary horror stars Lon Chaney Jr. and John Carradine do not appear together in any scene in it.
Lon Chaney Jr.'s character sports small goat horns on his forehead, perhaps the only reason for one of this film'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."
The final film of Sabrina.