Trick 'r Treat (2007)
Four interwoven stories that occur on Halloween: an everyday high school principal has a secret life as a serial killer; a college virgin might have just met the one guy for her; a group of teenagers pull a mean prank, and a bitter old recluse receives an uninvited guest. monster, grave, halloween, paranormal phenomena, undead, anthology, woods, serial killer, werewolf, corpse, school bus, holiday horror
ETC.
