Go to the bowling minigame (I believe it's in the kiddie land level... talk to the bunny in the middle of the level with the right number of carrots). Now, before hitting the bowling ball, try walking around. You'll be blocked by several invisible walls. But, go to either wall of the bowling alley and jump onto the green thing between the gutter and the wall, closer to the wall. You'll be standing there, looking around, but you'll be making a scruffy, slippy noise for no reason.