Factual error: When Dracula is about to bite the neck of his female assistant you can plainly see him in her vanity mirror and as all good horror fans know, you can't see a vampire in a mirror, especially Dracula.
Factual error: In no place on Earth does the full moon occur five times in a row, as it is in the movie.
Answer: The monster may have seemed obedient, but its overall behavior is unknown to us. It's possible that it was at times defiant, obstinate, or just didn't follow instructions completely or competently. It's also just a plot device for a silly movie. There has to be some reason, however flimsy, why Dracula wants Wilbur's brain.
raywest ★