Mother Hydra is a gigantic creature and alongside her consort Dagon is said to rule over the Lovecraftian race known as the Deep Ones. There is debate as to whether or not Mother Hydra is a lesser Great Old One or merely a grotesquely mutated Deep One - though the latter seems more likely as she doesn't seem to show much in the way of supernatural power outside her gigantic size and unnaturally long life span.