Batduck

At any time, you may trick-or-treat a player you haven't trick-or-treated before.
Trick: You say Because I'm Batduck! If your opponent doesn't cower in fear, you get to take 2 pieces of their candy for free. That'll teach them.
After Batman's death, his spirit took the shape of a bat, forever searching for its home...and scaring innocent children into giving up their hard-earned candy.