How about a ghost?
OK, sure. How about a demonic and creepy “trick-or-treater” who carries around a blood-stained sack and kills to punish those who don’t abide by the all Hallows eve rituals? When you wear this officially licensed Trick R Treat Burlap Sam Mask you can look like the movie’s star monster. That makes sense. See, Sam wasn't just another trick or treater out collecting candy.