Captain Korok was the Klingon commander of a D5 class deuterium ship during the 2140s and 2150s. For five seasons he harassed a deuterium mining colony, taking the majority of the deuterium and leaving only the bare minimum so the colony could survive.
In 2152, Enterprise NX-01 arrived on the planet to obtain deuterium and became aware of the situation. When Korok arrived, the deuterium was not ready due to two damaged extraction pumps. He became angry and beat Tessic, the leader of the colony. He told him that he was not shown the proper respect and gave them four days to fill the quota.
Archer and his crew taught the colony how to defend itself, and the next time Korok came, they ambushed Korok and his crew and drove him off. Korok withdrew and told Tessic that he could find deuterium anywhere and that Tessic's deuterium wasn't fit for a garbage scow. (ENT: "Marauders")