This is a glitch in Super Mario 64 DS that will kill you. Again. First, go as any character to the Jolly Roger Bay painting room. There will be 2 black inlets on either side of the room. Most people/everyone knows that the one on the right leads to the secret aqarium. But what most people don't know is that the other one also leads to somewhere- certain doom! Jump into the one on the left. It will give you a 1-up. This is good, so you do not actually lose a life here! Go into the back left corner of the little box, and start running toward it. Do a slide kick (press A and R while running), and you will fly through into a black void and die!
Why it works Edit
There is a small seam in the corner. The slide kick move pushes you through, and you start falling. The game comes up with a simple solution- kill you.
Found on a GameFAQs FAQ.