Cruncher worked for Abel Crumpton, another Garvak on Earth. Crumpton had Cruncher follow Lettice Butts, a Zantoran in possession of the Egg of Abundance. Crumpton's men captured both Lettice and Harry Sullivan.
When Harry couldn't answer Crumpton's questions about the Egg, Crumpton had Cruncher torture Harry.
Later, when Crumpton tried to activate the Egg, the process failed because Harry had switched the Egg with an egg. Crumpton's machine focused power through the egg, turning all the Garvaks, including Cruncher, into chickens. Cruncher was one of those who died when the building burst into flame. (PROSE: The Man from DOCTO(R))