Humphrey Bogart said of this film: "This is one of the pictures that made me march in to Warner Bros. studio chief Jack L. Warner and ask for more money again. You can't believe what this one was like. I had a part that somebody like Bela Lugosi or Boris Karloff should have played. I was this doctor, brought back to life, and the only thing that nourished this poor bastard was blood. If it had been Jack Warner's blood, or Harry's, or Pop's, maybe I wouldn't have minded as much. The trouble was, they were drinking mine and I was making this stinking movie."
Boris Karloff was to star as Dr. X.
When Walter 'Wichita' Garrett reviews the press clippings, two of them refer to "Eugene Xavier", the remainder refer to "Maurice Xavier."