Koopa the Quick is a large Koopa that Mario races against in Super Mario 64. He will race you on the second mission at Bob-omb Battlefield and at the Huge section of Tiny-Huge Island. The aftermentioned place, he claims to be his home course. He will give Mario a Power Star if he wins.
There is a glitch in the beforementioned mission that allows the player to beat Koopa the Quick in 0 seconds. To do it, the player must get the Wing Cap and triple jump right in front of Koopa the Quick, but not too close. Then fly to the top of the mountain. Koopa the Quick will talk to Mario once he lands, though he is far away. Then the timer begins and ends at zero seconds. However Koopa the Quick never gets up there, so the star can't be obtained that way.