A scene that's closely comparable to a scene in "Indiana Jones: Raiders of the Lost Ark" shows a close up of a man's face melting down to the bone and his jaw falling off. Likely done for comedic effect but may upset some squeamish viewers. Very brief, however. Only lasts about 5 seconds.
While Al is tripping on LSD, we see an extended montage of surreal and nightmarish scenes. At one point, his face melts off, and in another, he is tied up on a conveyer belt moving slowly towards a giant shredding machine. No actual gore is seen (except for the face-melting, which is very obviously fake and silly-looking).
A zombie hand bursts out of a grave and grabs a woman's arm. Mild jump scare.