The Vigilator

Vigilators are arthropods that live just beneath the surface of the Sands in Draykh-Nahka. When prey wanders above one, a Vigilator is able to cause a controlled cave-in of the surrounding sand. It then quickly consumes its prey, using its multiple pincers and gnashing tooth-blades. No Vigilator has ever been recovered from the sand, so ideas of what they look like are mostly guesses.