Little is known of Catolax's early history. He was apparently a resident of the city of Ullek during the Second or Third Age. He trained to become a seasoned Slayer Master, possessing knowledge that today has been forgotten. For unknown reasons, Catolax travelled to the Desert Slayer Dungeon, a cave system found beneath modern-day Pollnivneach. The dungeon was apparently being used by an unknown evil at the time, as is evident in the many ancient technologies and carvings still present in the area.