Mark Ross Pellegrino (born April 9, 1965) is an American actor of film and television. He is best known for his work as Lucifer in Supernatural, Paul Bennett in Dexter, Jacob in Lost and as Bishop in Being Human. He also recurred in the role of Clayton Haas in the ABC thriller Quantico.
Pellegrino appeared in season 7, episode 3 of The X-Files in November 1999. In 2001, he played an incompetent hitman in David Lynch's critically acclaimed Mulholland Drive. Pellegrino starred as Rita's abusive ex-con former husband Paul on Showtime's Dexter; and later as Lucifer on Supernatural and as the mysterious near-immortal Jacob on ABC's Lost. He has appeared on the television series Northern Exposure, ER, Without a Trace, NYPD Blue, CSI: Crime Scene Investigation, and Knight Rider.
He played the "Blond Thug" who stuffs The Dude's head down the toilet and drops his bowling ball, breaking the floor tile, in the cult film The Big Lebowski. He was featured in National Treasure as the background FBI agent known as Agent Johnson. In 2005, Pellegrino appeared in the Academy Award winning film Capote, playing murderer Dick Hickock.