The sentient species of Chelidae were indigneous to the planet known as Castilon. Despite being amphibious, their preference was for terrestrial habitats above the water's surface. Their bodies were protected by a naturally formed shell, and a distinguishing characteristic was that males possessed facial hair, unlike the females. Chelidae possessed the ability to decelerate their biological processes. Notably, a contingent of Chelidae functioned as engineers aboard the space station named Colossus.