"Sally Blackteeth", "Saskia Harden", and "Jenny Greenteeth" were aliases of a Water Hag whose real name was almost incomprehensible to humans. Because she was traveling when Strepto disappeared, she was the sole survivor of the Water Hags.
After traveling through the Rift to Earth in the Middle Ages, she made her home in Greendown Moss. 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 Three, who were alerted to her existence following her murder of Big Guy. (PROSE: Something in the Water)