John Schuck is no stranger to Star Trek, either... he's probably best-known for playing the Klingon Ambassador in Star Treks IV and VI. His delivery of the line "know this -- there shall be NO PEACE so long as Kirk lives!" is one of my favorite Klingon lines in all of Trekdom.
He also had a role in DS9 as Cardassian Legate Parn in "The Maquis: Part 2," and was in an episode of Voyager ("Muse").