Malgyorg

Malgyorg is an enemy in The Legend of Zelda: Spirit Tracks. It's encountered in the Sand Realm and basically acts like a Gyorg on land. It swims through the sand and when it gets ahead of the train, turns around and leaps to attack the train. Malgyorgs can be killed with one shot from the Cannon.

Blowing the train's whistle causes Malgyorgs to jump, making killing them easier.