Queen bat
From Tardis Wiki, the free Doctor Who reference
The Spectrox Bats are bats native to Androzani Minor. The bats are large, hairy, bat-like mammal who live in the caves carved out 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 Spectox, 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)