Klag was the second officer of the Klingon ship Pagh, who challenged Riker when he took the post of first officer.
Klag served as second officer on the Klingon ship Pagh under Captain Kargan in A Matter of Honor. When William Riker came aboard as the exchange first officer, Klag tested him, and Riker answered the challenge by knocking him down, earning the respect of the crew.
The two later came to understand each other. Klag spoke of his father, who had been captured by Romulans and was regarded as dishonoured, and Riker encouraged him to see the old man's worth. Klag stood with Riker when he took command of the Pagh. Brian Thompson played him.