The Yugai were a race that existed tens of thousands of years ago.
Some time less than 21,000 years ago, the Yugai established a colony on Botchok (Rigel VIII). They were the first species to encounter the native Orions, when a number of the then-primitive species attacked a Yugai colony. As no native sentient life had been previously observed on the planet, it was a surprising incident. But the Yugai commander merely destroyed the attackers and their village and promptly forgot about them. (FASA RPG - The Orions module: Book of Common Knowledge)