Mudskipper

A mudskipper was a type of amphibious fish found on Earth. It was capable of walking on land.

Martha Jones thought Mervin the Missing Link looked like a hairy mudskipper. (PROSE: The Last Dodo)

They were shown in a propaganda video, used to falsely suggest that the Monks had "shepherded humanity through its formative years". (TV: The Lie of the Land)