Mark Metcalf is an American actor in both television and film who is best known for his role as The Master in both television programmes Buffy the Vampire Slayer and Angel.

He is likely most known to two different generations for two notable roles. In the college comedy National Lampoon’s Animal House (1978), he played the sadistic ROTC leader Doug Neidermeyer. He played a very similar character in the Twisted Sister music videos “We’re Not Gonna Take It” (as the father) and “I Wanna Rock” (as a high school teacher). In each video he used his Animal House catchphrases, “A Twisted Sister pin?! On your uniform?!” and “You’re all worthless and weak!” respectively. He portrayed a very similar character in the movie The Stupids and the sitcom Teen Angel. He also starred in the 1986 comedy One Crazy Summer, as the sinister, greedy lobster loving Aquilla Beckerstead.

In the police drama Hill Street Blues Metcalf had an early key role in the first series as brash Officer Harris, often clashing with gentle partner Officer Santini. However, the role was cut short when Metcalf’s character was murdered in the episode ‘Up in Arms’.

In the 1997–2003 television show Buffy the Vampire Slayer and its spinoff, Angel, Metcalf played the ancient vampire supervillain, “The Master”. Coincidentally, he also played a character called “the Maestro” (real name: Bob Cobb) on two episodes of Seinfeld.