Son of Celluloid is a novelette written by Clive Barker. It was first published in the 1984 collection Books of Blood, Volume III.
Plot[]
An escaped convict dies behind a film screen. Over the years following his death, a cancerous tumor gains sentience from the strong emotions of the cinema's audiences and torments the few people that remain after one show. The sole survivor of the massacre is seen some time later, having tracked down the murderous entity which has roamed the country after possessing the body of a young girl. She then kills the creature with acid.