Xenorcinus are large aquatic carnivores native to the deep sea areas of Thanatos. They are the last of an ancient line.
Xenorcinus are large vertebrates, around 100 feet long and weighing up to 25 tons. Their mouths are wide like those of a Terran catfish, with shark-like teeth, and their bodies are covered in an exoskeleton-like armor. They have two vestigal eyes, which can no longer see. The torso is thick and similar to that of a crayfish or lobster. They have four large, ray-finned fins and a long, fluked tail.
Coloration can be either black or dark-brown.
Xenorcinus are carnivores. They have a specialized diet consisting of large deep-sea animals such as cerariders, as well as corpses that sink down from above.
Despite being the only survivors of the Xenorcinidae family, xenorcinus are relatively safe from extinction as of now, having a stable population.