17. Just scary
Some of the weirdest roommate tricks really cling to the primeval fears that we could never really overcome in our childhood. Do you remember that you constantly had nightmares of shadowy beings trying to kill you? Well, at the end of the hall, one is waiting for you, right when you go to the bathroom in the middle of the night.
It's nothing out of the ordinary, just a rough cut, black-cut piece of construction paper perfectly positioned for a nocturnal fear. This roommate prank manages to effectively combine our fear of home invasions with these supernatural beings. "Our parents always told us they were not real. To be honest, what is it about faceless beings that they so deeply disturb us?