Uso Yso was a swoop bike shop owner on the planet Euceron. He was two meters taller than Jedi Master Obi-Wan Kenobi. He had fifteen fingers on each hand that were the size of a bantha haunch, and possessed two beating hearts.
In 26 BBY, the Galactic Games was held on Euceron. Yso was in charge of the illegal betting that occurred. He made a bet with Didi Oddo and won. But under false pretenses, Didi tried to use Kenobi in order to get his credits back. This failed, but it did give Kenobi information that led him to uncover a plot by high-profile members of the Commerce Guild and the Galactic Games Council to discredit several senators who opposed them in legislation that would bring the guild members power, prestige, and untold wealth through the control of banking practices in the Core Worlds.
- Jedi Quest: The Dangerous Games (First appearance)