Snorkel Snake
The Snorkel Snake is featured in Yoshi's Story. It would prowl the Yoshi Sea, waiting for an unsuspecting Yoshi to attack. When it spots a Yoshi, it would swim in circles around him. However, its body is not long enough for it to make a complete circle, and there will always be an opening for the Yoshi to quickly swim out of.
It resembles a large, white serpent with green spikes and a large fin for a tail. Its head is a large ball with red eyes, flippers, and a spout for a mouth. It is invincible since Yoshi can't throw eggs underwater.
It is unknown if Snorkel Snakes are a species. Oddly, the Snorkel Snake's spout can't hurt any of the Baby Yoshis, but all the other body parts can.
In New Super Mario Bros. U a similar enemy called Dragoneel appears, as they both try to encircle players with their bodies.