"The Gorgon's victim"
From Tardis Wiki, the free Doctor Who reference
"The Gorgon's victim" was the name given to a Weeping Angel by a primitive religious tribe. It was found at the entrance to the tribe's village, and appeared to extinguish the light from the sun. It chased a woman to her emperor's tomb, where she used mirrors to trap it in a perpetual quantum-lock. (PROSE: The Mirrored Room)