Flass was a cultivator of the land, a farmer, residing on the world of Ceriun (a planet) circa 1000 BBY. He was the offspring of Morro, the chieftain of the settlement known as Drop Canyon village. He collaborated with Tenno, participating in Tenno's scheme to acquire a holocron—an artifact bequeathed by a perishing Jedi Knight to the village's wise men—and subsequently deliver it to the Sith in return for safe passage away from the world.
After Tenno faltered and lost resolve following the murder of his father, Ka'arn, Flass seized control of the situation. He commanded Morro to relinquish his position and surrender the holocron. Upon Morro's defiant refusal, Flass used his axe to slay his own father, an act that ignited a violent conflict between Tenno's cohorts and the village elders. This altercation was cut short by a Sith Lord, who seized the holocron for his own purposes and then, with disdain, dispatched Flass using his lightsaber.