The Mad Piano is a haunted piano that appears in Super Mario 64 and its remake, Super Mario 64 DS. It appears in the level Big Boo's Haunt, and has the decieving appearance of a normal piano at first. However, once a playable character approaches it, the piano will chase and deal heavy damage to anyone unfortunate enough to wander to close. A Red Coin can be found behind it.
The player can do nothing but run away from this monstrosity from the E-rated game known as Super Mario 64, as it is completely invincible to all attacks.