Manta

The Manta or Manta Ray is a character from Super Mario 64. It resides in the level Dire, Dire Docks, where it swims in a circle around the whirlpool in the center of the entrance area. The Manta will leave a trail of shimmering rings as it swims around the whirlpool. If Mario can swim through five rings in a row, he'll be rewarded with a Power Star. Fortunately, he can swim through a ring to regain lost oxygen. Unfortunately, if Mario misses a ring, he has to start the five ring sequence all over again. If he swims through a ring correctly, a red number will appear. When Mario accomplishes the five ring task, the Power Star will appear at the top of the whirlpool. If Mario gets too close to the whirlpool, it will suck him in. Mario should also keep his distance from the Manta's tail, as it can deal damage.

In Mario Party 4 there is a mini-game called Manta Rings in which Manta releases Manta Rings while swimming.

It also makes a reappearance in New Super Mario Bros. when playing two players with both cartridges.