Despite writer / director Paul Annett's objections, producer Milton Subotsky (who hated this film) insisted on the "Werewolf Break" gimmick, where the viewer was invited to guess who the werewolf is.
Due to the film's small budget, the werewolf was played by a German Shepherd Dog.
Hammer Films and Amicus Pictures produced numerous horror films involving vampires, ghosts and devils over a period of 20 years, but both of them only produced one werewolf film each. This was Amicus' film; Hammer's film was The Curse of the Werewolf (1961), an early starring vehicle for Oliver Reed.
Robert Quarry was originally slated to play the lead in this film, but at the last minute the producers went with
Calvin Lockhart instead in order to capitalize on the then-hot blaxploitation craze.
One of the unforeseen challenges of casting a black actor in this film was that it caused problems with lighting the numerous
day-for-night scenes in it, which is a cost-cutting method where nighttime scenes in a film are shot in the daytime with the
addition of special filters in the cameras to make them look like they were filmed at night.