Sarpek the Fearless was an historical Klingon figure, famed for unearthing the Knife of Kirom. It was said he accidentally found the Knife while looking for his lost targ.
In 2376, while researching great discoveries in Klingon history, Neelix learned of this story. He related it to B'Elanna Torres. (VOY: "Barge of the Dead")
This character was only mentioned in dialogue.