Thal K'sar was a member of the Bith species, and he was an employee of the Commerce Guild.
Around the year 33 BBY, K'sar was working as an artisan. He contributed to the design of the hyperwave transceiver and the holoprojector that were integrated into the mechno-chair used by Nute Gunray, the Viceroy of the Trade Federation.
By the onset of the Clone Wars, K'sar had received a promotion to an executive position and was assigned to Escarte.
In 19 BBY, K'sar was taken into custody and given a death sentence. The official reason for his execution was an accounting mistake he supposedly made, which would cause the Guild to lose a substantial amount of money. However, the true reason was that Darth Sidious was trying to eliminate individuals who could connect the captured mechno-chair back to him. Fortunately, Anakin Skywalker and Obi-Wan Kenobi, who were Jedi Knights, intervened and saved him. K'sar then informed the Jedi Knights about another mechno-chair he had worked on, which had been installed on a prototype vehicle. When the Jedi requested information, K'sar revealed the location of the pilot who had been hired to operate the vehicle: he could be found on the planet of Naos III.