Sally Blackteeth was one of the better known aliases of the only Water Hag to survive the disappearance of Strepto. Among her other aliases were "Saskia Harden" and possibly "Jenny Greenteeth". Her real name was almost incomprehensible to humans. Greendown Moss was one of her homes.
Sally's birth predated the Middle Ages. She died some time in the late 2000s when she tried to travel through Cardiff's space-time rift and was shot on sight by all five members of Torchwood 3. (PROSE: Something in the Water)