One person drops the rat/ sock down the tube; the other person (the splatter) is poised with a bat and has to hit it when it comes out of the tube before it hits the ground. The guy in the picture is actually cheating, you shouldn't already have the bat near the tube exit.
It is really funny because it is actually really difficult and you and the people around you get really tense with anticipation. You guys have to try it, it's hilarious!
