Gyreworm

From Twilight Wiki

Gyreworms are earth elementals in the shape of a tunneling worm and are native to Deepholm although they have appeared in Kezan as well. Their purpose appears to simply be eating away rock and minerals. Earth elementals serving under Therazane the Stonemother consider these worms as vermins.

Although elementals, most are classified as beasts in-game, except Corborus. Whether this is an error or will allow them to be tamable by hunter as a worm is unknown at this time.