Geek Maggot Bingo or The Freak from Suckweasel Mountain (1983)

In this darkly humorous movie, we follows the deeds of mad Dr. Frankenberry and his hunchbacked henchman, Gecko. As the two insane castle dwellers create their grotesque, two-headed Formaldehyde Man, down underground, Vampiress Scumbelina leads a vampire mob.