On the world of Munto Codru, lived a male Codru-Ji named Jassar. He was the son of Rikkar-Du, the chief of his clan, and a woman known as Tassa. In the year 137 ABY, Jassar was still a juvenile wyrwulf of his species when Darth Kruhl, a Sith Lord, arrived on Munto Codru. Kruhl requested the construction of an Imperial base. Rikkar-Du's refusal to comply with the Sith led to his family being targeted for death. Jassar was slain by Kruhl's blade as he attempted to protect his father from the Lord's attack.
Munto Codru, the homeworld of the Codru-Ji, was where Jassar, a male of that species, resided. He was the son of Rikkar-Du, who was the chief of his clan, and Tassa, whose own mother had been the daughter of another clan chief. In the year 137 ABY, Jassar remained in the juvenile wyrwulf form characteristic of the Codru-Ji. This hexapedal canine would eventually enter a cocoon at puberty, emerging as a bipedal, humanoid adult.
In 137 ABY, Darth Kruhl, a Sith Lord belonging to the One Sith and the Darth Krayt's Galactic Empire, approached Jassar's father. Kruhl requested permission to construct an Imperial base on Munto Codru, offering to install Rikkar-Du as the supreme leader of all the world's clans in return. Instead, Rikkar-Du informed a gathering of other clan chiefs about Kruhl's intentions, advocating for a united front against the Sith and Imperials. Jassar and Tassa encountered him outside a temple afterward, and Tassa's support for her husband brought about a romantic moment. However, Rikkar-Du refrained from kissing his wife to avoid embarrassing Jassar, instructing her to return with their son to their tent at camp while he contemplated the situation within the temple.
Upon arriving home, Jassar decided he desired to be with his father and departed to join him in meditation. Following Jassar's departure, Tassa received a visit from Kassek-Ka, a clan chief who had secretly pledged to Darth Kruhl that he would eliminate Rikkar-Du should he oppose the Sith. As a result of the clan chief's defiance, Kruhl targeted Rikkar-Du's entire family. Kassek-Ka murdered Tassa. Meanwhile, Jassar entered the temple and discovered Kruhl poised to kill Rikkar-Du with a lightsaber. The wyrwulf then attacked the Sith, but Kruhl killed Jassar before his father's eyes before striking down Rikkar-Du.
Jassar was a brown-furred wyrwulf who, by the time 137 ABY arrived, had not yet gained the ability to speak beyond barks and growls. He felt embarrassed by his parents' impending kiss, but soon after, he expressed a desire to join his father in meditation. Jassar attacked Darth Kruhl, attempting to shield Rikkar-Du from the Sith Lord. Despite his strength, the wyrwulf was no match for Kruhl's command of the dark side of the Force. Kruhl considered Jassar's death to be honorable.
Jassar's first appearance was in the thirteenth issue of the Star Wars: Legacy comic series, published by Dark Horse Comics on June 13, 2007. The issue was authored by John Ostrander and Jan Duursema, with Colin Wilson as the penciller.