Kaybok was a high-ranking officer of the Klingon Defense Force and the commander of the IKS M'Char, a Klingon Bird-of-Prey.
In 2372, Kaybok used the M'Char to trap the Xhosa in its tractor beam. The USS Defiant was launched from space station Deep Space 9, when Benjamin Sisko received a priority 1 distress call from Kasidy Yates, the captain of the attacked freighter. When the Defiant contacted Kaybok, he told the Starfleet crew that the Klingon High Council had issued him orders to search every ship that tried to leave Bajoran territory. The Defiant responded by attacking the M'Char and the Bird-of-Prey eventually left the area.
When General Martok left Kaybok's d'k tahg with Sisko, Jadzia Dax explained that the Klingon commander was dead. Dax added that Kaybok had probably been executed under Martok's command as punishment for disobeying orders. Worf later discovered that Kaybok had been executed under Martok's authority because the commander had refused to fire on the Defiant. (DS9: "The Way of the Warrior")
Martok's wish for a Federation vessel to be attacked by a Klingon Bird of Prey was later discovered to be part of a larger ploy by the Changelings to start a major conflict between the Federation and the Klingon Empire. The "Martok" who had been commanding the Klingon fleet, which included Kaybok's ship, was himself in fact a Changeling. (DS9: "Apocalypse Rising")