Piranha Plant

Piranha Plants are enemies in Super Mario 64. They have green stems, 2 green flowers on opposite sides of the stem, a red head with white dots and large green lips hiding teeth. They sleep when not provoked, and when approached, the Piranha's Lullaby music plays which cannot be found anywhere else. If provoked, they will wake up and attempt to bite the player, dealing damage. They will go back to sleep when the player leaves it's vicinity. If jumped on before awakening, they will be defeated and drop a blue coin. They will respawn later, but not drop a new blue coin. They have a variant know as the Piranha Flower.

Overbite
There is an unused Piranha Plant animation for the enemy sleeping with their teeth showing, used in earlier builds of Super Mario 64.