You Better Watch Out | 1980
One Christmas Eve when Harry was a child, he was traumatized to see his father, who was dressed as Santa, having sex with his mother. Now a grown man, Harry works for a toy company, sleeps in a Santa suit, and spies on the kids in his neighborhood to see "who's been bad or good." His brother Phillip has begun to worry about Harry's mental balance, and one day he does snap. Dressed as Santa, he steals a truck full of toys and takes them to a mental hospital to give to the children there. But when Harry runs into people who don't believe he really is Santa, he goes on a killing spree.