Gigantic Behemoth, native to the Far South,-- a monstrous many-toothed worm that burrows under the dunes, large and hungry enough to consume entire armies,-- which harnessed by the Mask Of Alabaster during the Balorian Crusade and set on Chiaroscuro. It was driven back, but not killed, by the Dragon-Blooded "Kevah Althune?", one of the Seven Tigers.
...yes, its a Sand Worm. <.<