Here's a nice, friendly Halloween prank. (We promise there's no Slender Man involved.) A friendly group walked around with candy and a door with a sign on it (advising people to knock, we guess).

Once people knocked, they were treated like Trick or Treaters and given candy and compliments. Perhaps the real prank was that the guy opened the door backwards almost every single time and nobody noticed. Awwwww, snap! Now *that's* a prank!