The Gyorgs in The Wind Waker are fierce-looking, shark-like enemies that inhabit certain parts of The Great Sea. If Link encounters a Gyorg while sailing, it will attempt to knock Link out of his boat, the King of Red Lions, by ramming it head-on. It can also attack Link by biting him should he encounter one in the water.
A different form of Gyorg appears in Spirit Tracks under the name of Malgyorg, and they reside in the sands of the arid Sand Realm rather than in the Ocean. It acts and looks the exact same as Gyorgs from The Wind Waker. However, they are yellow in color rather than the original purple. They are much larger than their oceanic cousins. They usually travel in groups that range from two to four. Since they only appear while Link is roaming the overworld on the Spirit Tracks, the Cannon is the only weapon capable of defeating them.
Picture of Malgyorg by Metallic, designed by Sabidiet