User blog:The one true evil/Joker weapon idea (non)contest

Just a random thought I came up with after thinking of all the crazy weapons/gadgets the Joker uses and thinking up one of my own. So I invite anyone to come up with a crazy prank themed weapon/gadget (note it doesn't strictly speaking be prank themed)

The rules:
 * think of a weapon or gadget the Joker would use
 * describe the gadget and how it works
 * this is not a contest

Now I'll give an example:
 * Name of gadget: Gatling Gun in the Box
 * What it is: exactly what it says on the tin
 * Instructions:
 * step one: aim lid at target
 * step two: turn crank until gun barrel pops out
 * step three: continue to turn crank to fire bullets