Malgyorg

Malgyorgs are enemies from The Legend of Zelda: Spirit Tracks. These shark-like enemies swim in the sands of the Sand Realm, waiting for the Spirits' Train to approach. When this happens they lunge out of the sand and attack the train. The only way to defeat them, is to blast them with the Cannon when they are airborne. To make this easier, the train's whistle can be blown to make all nearby Malgyorgs jump in the air.

Etymology
Malgyorg's bear resemblance to Gyorgs from The Legend of Zelda: The Wind Waker and Phantom Hourglass, and are likely named as such.