Silent Night, Deadly Night: The Official Novelization of the Original Movie

Synopsis

From the publisher website: "Christmas Eve, 1971... Five-year-old Billy Chapman witnessed his parents brutally murdered by a man disguised as Santa Claus, leaving him and his little brother to be raised in a strict Catholic orphanage ruled by the sadistic Mother Superior. December, 1984... Eighteen and finally on his own, Billy sets out to live a normal life. Landing a job at the local toy store, he's forced to play Santa Claus for the holiday season. Still in his red suit at the employee Christmas party, Billy snaps, going on a violent rampage, punishing all those he deems "naughty." Now, with one last gift to deliver, Billy makes his way back to the orphanage, where he has an axe to grind with Mother Superior."