What are the aliens for Doctor Who planet of the dead?

Answer 1

They are called 'Stingrays', they weren't really given a proper name.

Stingrays were ray-like creatures, with a wide head, a long tail and fins down their side. They were the size of a small car, but were still capable of flight at speeds of at least 300 miles per hour. They were extreme omnivores, capable of eating plant, animal, rock or metal. Any metal they ate would be extruded into their exoskeleton, making them bullet proof, though not immune to explosives. Stingrays would go into hibernation when cold.