For those of you who have purchased Feast of the Preserver (thanks), you may enjoy this clip from the movie Monster Club (1981).
I watched this movie as a kid and the ghoul story has always stayed close to my heart. The seed for Feast of the Preserver is definitely in this movie. If you can, watch Monster Club, it's an amazing old school piece of schlock horror.
Feast of the Preserver is available from RPGNow.com.