First appearance: The Masque of the Red Death (1964)
The satanic Prince Prospero has invited a bunch of jerky noblemen to his castle while a horrifying disease lays waste to the surrounding countryside. He plans on converting a bunch of them to Satanism. Over an evening of horrible pranks and vengence Prospero begins to think that maybe putting his faith in the "Father of Lies" isn't the best of ideas.
This is probably my favorite of the Roger Corman Edger Allan Poe/ Vincent Price movies.
Highly recommended. So much fun.