Rokea

The Rokea are a terrifying species of shape-changing creatures that often are in the form of unholy, enormous sharks. 
They claim to be the first of the Changing Breeds, as Sea existed before solid land appeared on Gaia and sharks predate all land-born predators. Rokea are effectively immortal. They can not die naturally; once they reach adulthood, their aging process stops. The only way a wereshark can die is through an unnatural death. They are constantly compelled to move, and have trouble standing still even on dry land. Most Rokea are notoriously xenophobic, and very few leave the water.