Queen bat
From Tardis Wiki, the free Doctor Who reference
Spectrox Bats are large, hairy mammals who live in the caves of Androzani Minor. They have a three year life cycle, some of which is spent in a chrysalis. These chrysalis have a large supply of unrefined Spectrox, which is refined and used by the Humans of Androzani Major. These bats were killed or driven out by the mining androids, which caused them to move into the airless caves deep underground to die. (DW: The Caves of Androzani)