Have 2 players, one as Ness and one as Mario or Dr. Mario. Have Ness use PK Thunder (up+b) into his head (Must send himself into the opponent's direction). When ness is about to hit Mario/Dr. Mario, use Mario's forward B (Cape). Ness will do something "funky", and he may go through the ground, if you have the right version of the game.
Submitted by: Jesse