Coffin-Loaders were an insectoid scavenger species that came down on a doomed planet. The Second Doctor wanted to know why they came to Cosmic Finance Central Five. The Third Doctor later saw some in a facsimile of London and destroyed Waterloo station. They were kept there to be hunted for sport. There was one on Gerry Lenz's ship and it escaped in London. (AUDIO: The Three Companions)