None of the Hellboy movies managed to completely translate Mignola’s style to the screen, neither the live action movies nor the animated ones. This episode on the other hand is like a Mignola comic come to live. It’s the pilot to an unrealized TV-series based on one of the wackier concepts of Mignola (admittedly, they are all quite wacky).
Like Hellboy it has a hero fighting mystical bad guys that intent to end the world via occult means. Unlike Hellboy, it doesn’t take itself very seriously and is much more funny. The hero is a screw-on head, the villain one of his earlier butlers who became a zombie because he lusted for the dark arts and so on. I admit I can’t imagine that this kind of thing would have worked for more than a season. But that season could have been quite funny.