Megalobite

It lives out in the blue past the ruins, rising only to hunt, and its hunt is less a chase than an event: a shadow that becomes a wall of teeth with no interval between. It navigates by the faint electric signatures of living things, so darkness and depth hide nothing from it. For all its menace it is a slow breeder and a long-lived one, and old sailors around Ixqun speak of individuals they claim to have known for decades, always with lowered voices, as if the sea might be listening on its behalf.