Atlantern

It drifts the black depths around the Ruins of Ixqun trailing the brilliant luminous lure of its shell, and in a world of total dark that light is both hunting-lantern and throne, drawing curious prey to within reach of its powerful grasp. Its shell is a genuine fortress, thick enough to turn nearly any attack, so the Atlantern hunts and is hunted by almost nothing. It is drawn to the drowned architecture of the ancient ruins, and divers tell of vast Atlantern hanging motionless in flooded temple-halls, their light pouring through the pillars, as if standing some patient, luminous vigil over the secrets Ixqun keeps.