Grack was a figure in Klingon folklore.
Biography[]
Supposedly, Grack and Krak were bandits who attempted to rob Gorath, but were scared off by his bat'leth.
Much later, as recounted in a different story, the two of them became beggars and took Kahless the Unforgettable in when he became ill. (ST episode: "Klingon Fable: The Legend of Gorath")