MIPS
MIPS is a rabbit found in the basement of Peach's Castle during the events of Super Mario 64. When Mario approaches the bunny, MIPS will run away. After Mario catches MIPS, the rabbit gives him a Power Star. MIPS appears in the basement a second time after Mario defeats Bowser.
MIPS also reappear in Super Mario 64 DS as a species that came in pink, green, yellow, and blue. Each color can only be seen and caught by the character he is matched with. Each rewards a new mini-game and if all are caught, the key to the previously unopenable door in the the character switch area becomes accessable.
Apparently, MIPS is late for an important appointment.
MIPS gets his name from the measure of a computer's processor speed, which is measured in Millions of Instructions Per Second.