Rabbit

Rabbits are a species within the Super Mario series. In Super Mario 64, MIPS the Rabbit appears as a character in the castle basement. However in the game's remake, Super Mario 64 DS, MIPS is replaced by an assortment of unnamed rabbits. These unnamed rabbits can also be found scattered around the castle with positions and colours dependent on the character that's currently being played. These rabbits will drop keys for the corresponding character's minigames. These rabbits can also appear white and glowing, and will drop keys to unlock one of the castle's secret stars.

Trivia

 * An unknown purple rabbit appears within Super Mario 64 DS' instruction manual, which has led many to believe that this rabbit belongs to Waluigi who has been heavily rumoured to be in the game.
 * In Super Mario 64 DS, the rabbits are internally known as "MIP" and drop "MIP Keys".