T'chooka D'oon was a dark-skinned Jedi Master of the Old Republic. In his younger years as a Jedi Master, T`Chooka D`oon was best known for his involvement in the Huk War fought between the insectoid Yam'rii and the primitive Kaleesh of the planet Kalee. Although the Yam'rii were the aggressors in the conflict, the Kaleesh army, led by Qymaen jai Sheelal, otherwise known as General Grievous, managed to expel the Yam'rii from Kalee. As they pushed the invaders back across their conquered worlds, and were eventually conquered themselves. The atrocities committed by the Yam'rii elicited a bloodthirsty vengeance in the Kaleesh who showed little mercy to the Yam'rii army as well as their citizens.
Backed by the Trade Federation, the Yam'rii appealed to the Republic for help. In response, the Republic sent a team of Jedi to mitigate the conflict. Masters T'chooka D'oon and Jmmaar led the envoy at the behest of the Republic Judicial Department. Under pressure from the Senate, Masters D'oon and Jmmaar were constrained to rule in favor of the Yam'rii and imposed sanctions and war reparations on the Kaleesh. With the help of the Jedi, the Huk War was officially ended. The punishments were devastating to the Kaleesh economy.
The failing economy led to starvation and increasing acts of barbarity as the Kaleesh struggled to survive. Qymaen lost many family members to the horrors following the war. Witnessing this, the Kaleesh general began to harbor an increasing hatred for the Jedi, especially Master D'oon who acquired the moniker 'The Executioner of Kalee.' Years later during the Clone Wars, Qymaen, as the cyborg General Grievous would be reunited with T'chooka giving him the opportunity to exact his revenge on the Jedi Master.