Yoshi's face messed up

From Glitches

From the game Super Mario 64 DS for the Nintendo DS.

This can only be done at Tall,Tall Mountain. Go to Tall Tall Mountain as Yoshi. Go to where the monkey is. Watch for the flying shy guy to spit a fireball. Eat the monkey JUST BEFORE the fireball hits you and run into the water. Don't go down the waterfall. Yoshi's face will look distorted, and the inside of his mouth will be black. Exiting the level will fix this.