From "Supernatural Exclusive: Matt Frewer Cast as One of Four Horsemen"
Supernatural has cast another of the Four Horsemen of the apocalypse.
Matt Frewer — best known for a recent role in Eureka and for playing the title character on Max Headroom — has been cast as Pestilence, TVGuide.com has learned exclusively. Pestilence creates and spreads disease.
"Our first brush with him in Episode 520 seems relatively innocuous and then unfolds into something more substantial," executive producer Sera Gamble said. "Put it to you this way: Horsemen on our show tend to think several moves ahead."
Throughout Season 5, we've met two of the Four Horsemen. War (Titus Welliver) and Famine (James Otis) have appeared, while the fourth Horseman, Death, has only appeared off-screen in one episode.