Stormcrow
From Tardis Wiki, the free Doctor Who reference
The stormcrow was a carrion feeder, devouring dying or dead worlds, circling them for millennia, on their dark side. Every thousand years one of its kind came to Earth to taste it and see if its time had come.
Symbiotic creatures called No Things lived under its wings. (AUDIO: Night of the Stormcrow)
