Mark Metcalf (born 11 March 1946; age 78) is the actor who played the Hirogen Medic in the Star Trek: Voyager fourth season episodes "The Killing Game" and "The Killing Game, Part II".
He is better known, however, for playing Doug Neidermeyer in National Lampoon's Animal House (1978, with Bruce McGill) and as "the Master" on Buffy the Vampire Slayer. He also played the abusive father in the music video for Twisted Sister's Top-40 hit We're Not Gonna Take It. Metcalf appeared in two episodes of Seinfeld (starring Jason Alexander). Soon after his Voyager appearance, he would appear in three episodes of JAG as a naval officer named Captain Pike (who was given his position after Terry O'Quinn's recurring character was promoted to Admiral).