Jmmaar was a Viraanntesse Jedi Master from the planet Vvaw and a member of the Jedi Order leading up to the Clone Wars. The Viraanntesse were a species of crab-like beings with ten legs making Jedi Master Jmmaar a particularly intriguing sight even among a galaxy of infinitely strange creatures. Jmmaar was best known for his involvement in the Huk War where he served as a mitigator between the primitive Kaleesh and the insectoid Yam'rii. In their remote region of space, the Yam'rii launched a massive colonization effort that resulted in the conquering of many worlds. When the insect invaders arrived to Kalee, they saw the native Kaleesh as a viable source of slave labor. Not willing to submit to such a fate, the Kaleesh fought back with a ferocity that was fueled by the atrocities committed by the Yam'rii.

The Kaleesh were led by a young general known as Qymaen jai Sheelal, who would come to be known as General Grievous during the Clone Wars. Under the command of jai Sheelal, the Yam'rii were pushed back across the star system as the Kaleesh claimed worlds previously conquered by the invaders. Pushed back to the planet of Tovarskl, the Yam'rii had had enough and pleaded with the Republic to intercede. The Republic Judicial Department requested the Jedi to intervene and an envoy was sent by Master Jmmaar and Jedi Master T'chooka D'oon. Because the Yam'rii were backed by the Trade Federation, the organization used its considerable pull in the Senate to push for a decision favorable to the Yam'rii.

Under such pressure, there was little Master Jmmaar and T'chooka D'oon could do otherwise. The two Jedi ruled against the Kaleesh imposing economic sanctions and war reparations. The decision destroyed life on Kalee, as it caused the economic structure to crumble. Hordes of Kaleesh citizens died from the starvation and the ensuing breakdown in society. Qymaen jai Sheelal lost many of his own family members in the chaos and developed a deep hatred for the Jedi he believed to be the cause of it all. A particular hatred emerged for Jedi Masters Jmmaar and D'oon, as they were the ones who handed down the decision. In his second life as General Grievous, fate would bring Qymaen and Jmmaar together once more during the Clone Wars.