A crocodilian was a living thing which generally resembled a crocodile. There existed many crocodilian species across the cosmos. The planet Sobek was ruled by a race of sapient Crocodilians, (AUDIO: The Skull of Sobek) and UNIT once had to deal with an aggressive, alien Crocodilian who was quadrupedal and six metres long, and piloted its own spaceship. (AUDIO: Vanguard)