Mad Piano

The Mad Piano is an average-looking piano appeared Super Mario 64 and Super Mario 64 DS. However, when a character as Yoshi, Luigi, Wario or Mario goes near the instrument, it will open and close its lid, revealing sharp teeth. The Mad Piano will then attack the trespasser until the heroes have to get out of the room where the piano lies. The Mad Piano only appears in Big Boo's Haunt. A Red Coin is found beneath it when the characters have the mission to pick up the 8 Red Coins hidden in the level. The Mad Piano sits there like a normal piano until Mario gets near, then it chases after him.

It is impossible to defeat this enemy, so it's best to just avoid it.

A Mad Piano possibly appeared in Mario Party 8 in King Boo's Haunted Hideaway, playing the Super Mario Bros. underground theme.