The Lady of Pain was a crime lord of the Rattataki species (specifically, female) who conducted her illicit activities on Tatooine in the era of the Cold War.
As a member of the Exchange and an organizer of gladiatorial contests, the Lady of Pain encountered Tyresius Lokai, a Devaronian who was being hunted during the Great Hunt in 3643 BBY. When Lokai's bounty hunter arrived at her compound, the Rattataki arranged a gladiatorial battle between the hunter and Borga, a Gamorrean working for Fell Dargun. Despite the hunter's victory, Lokai successfully fled the Lady of Pain's control before he could be delivered to the hunter.
Nika Futterman provided the voice for the Lady of Pain, and she also voiced Asajj Ventress in the TV series Star Wars: The Clone Wars.