I've seen references to Lon Chaney being the performer of choice for the role that was eventually played by Charles Bickford. As in the case of the Big House, however, this film was released before the Unholy Three, so how could Chaney have been slated for it?
Personally, despite the cool giant rays in the film, I'm glad that he didn't get the role. I doubt that it would have added to his prestige to be cast in what appears to be a B effort, IMO. Thanks!