Byrok was an elder orc who once participated in Gul'dan's dark schemes, but later returned to the old traditions of the orcs when Thrall liberated the Horde. He had also sworn eternal loyalty to Thrall.
However, he had not seen the last of the warlock yet. One day, when he was fishing, he saw humans wearing the symbol of the Burning Blade clan, who spoke of overthrowing Thrall. Byrok, angered by seeing human warlocks, attacked, but in the end, they were more, and they defeated him. Byrok was grievously wounded, but didn't die. 
Later, he was seen by none other than Rexxar himself. Rexxar, followed by his loyal bear companion Misha, found Byrok in the wilderness. The orc was in a bad state, but managed to say what had happened. Byrok was escorted to Orgrimmar safely by the Mok'Nathal. His status afterwards is unknown.