Kralk was a Klingon member of Klahb, and in 2379 participated in the attempted takeover of the Federation Embassy on Qo'noS.
Early in the takeover attempt, Worf was able to wound one invader and kill another. Seeing this, Akor called for backup and Kralk was sent along with B'Eko to help capture Worf. Kralk was never able to find Worf and eventually Worf was able to regain control of the security system and flood the building with anesthizine gas knocking everyone unconscious. Along with all of the surviving members of Klahb except for Rov, Kralk was captured and held by the Klingon authorities. (TNG novel: A Time for War, A Time for Peace)