This is nota code or a glitch, but it's true that by ding this you can make mario invisible for as long as you want. First, you have to be in the "Wing Mario Over The Rainbow" level. It's at the very top floor, and up on the wallto the right. Hop down into the level. You will start out on a thick cloud. Don't push any buttons for about 30 seconds. Mario will yawn and say he's tired, he'll lay down on his side, and the cloud is so thick that you can't see him!