A couple of actual skulls were used as props in the cave scenes at the end of the movie. They were having a lot of difficulty in filming the last scenes of the movie until this was found out and the man that played the Indian Shayman in the movie, actually performed an exorcism on the set and there were no problems after.
Contributed by: Philip Berry
H. R. Giger, the famous Swiss Surrealist artist, perhaps best known in the U.S. for his designs for the film "Alien," was hired to do the creature designs for the film (the tequilla worm-demon Kane and the limbo-world demon Kane). Some books on his art report that Giger was "very unhappy" with how his designs were translated to film in Poltergeist II.