Ruul, a male Zabrak Dathomirian hailing from the planet Dathomir, belonged to a clan of Nightbrothers during the Clone Wars. Before the events of the Second Battle of Dathomir in 19 BBY, Ruul collaborated with a team of mercenaries and Mak Eak, a Nightbrother chieftain, inside a warehouse-like building as part of a mission orchestrated by the fugitive Nightbrother Arzo Suun to procure resources for Eak. Ultimately, their scheme was foiled when Nelsel, at the head of the Nightsisters (a coven of witches who held dominion over the Nightbrothers), sensed their intrusion via the Force and apprehended them.
Ruul's name appeared in Collapse of the Republic, a supplementary roleplaying book for the Star Wars Roleplaying game series, released by Fantasy Flight Games in 2019.