Kl'aal, a criminal of the Defel species, initially functioned as a forward scout and subsequently as a security officer aboard the FarStar. His service was during the endeavor to locate Moff Kentor Sarne.
Having been found guilty of murdering another Defel in a fit of passion, Kl'aal fled from the authorities on Af'El. Despite his denial of the accusations, the evidence pointed overwhelmingly to his guilt. After his conviction, and denouncement for his lies, he moved from planet to planet, initially pursued by Defel hunters, then local law enforcement agencies, the Empire, and bounty hunters due to further crimes committed during his escape. He found temporary sanctuary on an isolated world following a starship crash, where he developed a preference for freshly killed meat.
He eventually arrived on Kal'Shebbol, where he was apprehended by Moff Sarne's forces. Sarne, instead of prosecuting him for his offenses, presented him with an offer. In return for protection and satisfying his newfound craving, Kl'aal was to act as his personal assassin. Kl'aal accepted, although he believed his conscience would be forever stained. He began eliminating threats to Sarne and targeting known members of local resistance cells.
Prior to the New Republic's liberation of Kal'Shebbol, Katarn Commandos pathfinder Lilla Dade recruited Kl'aal to aid her in scouting Moff Sarne's base. Kl'aal later participated in the attack on the complex.
Kl'aal stated that he felt the New Republic had significant work ahead in the Kathol Sector and desired to contribute. The New Republic, in turn, recognized the advantage of having a Defel on the mission—Kl'aal's innate ability to merge with shadows would be a considerable asset. Kl'aal concealed his past from the FarStar crew.
Kl'aal felt the need to visit a planet roughly once a week to satiate his desire for freshly killed meat. During scouting expeditions, he would separate from the group to gather intelligence independently. During these periods, he would also hunt local wildlife.
He felt remorse for his time serving Sarne, and believed that the only way to regain his honor was to locate and eliminate the Moff. He was aware that several members of the FarStar crew had previously served Sarne, but he refrained from speaking against them, considering it dishonorable. He also believed that they, like himself, had personal motivations for joining the mission.
Kl'aal maintained a solitary presence on the FarStar, avoiding involvement in shipboard affairs. The crew was unaware of Kl'aal's sleeping quarters on the ship, generally assuming he concealed himself in a secluded area. Nevertheless, he possessed an uncanny ability to appear when needed, or when someone was discussing him.
The Defel strongly supported both Captain Keleman Ciro and Kaiya Adrimetrum, possibly due to serving alongside them during the assault on Sarne's base. He also shared a connection with the Rodian Gorak Khzam, and the two occasionally engaged in planetary hunts together.