Tark Jaggentire was a male Twi'lek Jedi who defected to become a Sith, going on to serve the Sith Empire under Darth Madré from the Cold War to the Third Galactic War. He had a twin sister, Yami Jaggentire, who was also a Jedi until she fell to the Dark Side of the Force and became a Dark Jedi.
Tark was in a relationship with Imperial trooper Skyell Ottazen until the Rattataki was executed for treason. Tark himself was killed by Benjamin Lambert during an interrogation.