Mark Ross Pellegrino (born April 9, 1965 Los Angeles, California) is a American actor and acting teacher, best known for his compelling portrayals of complex, powerful, and often supernatural characters. Pellegrino has built a prolific career spanning television and film. He achieved widespread recognition for his iconic roles as Lucifer in Supernatural and the mysterious island protector Jacob in Lost. His other prominent television credits include Dexter, Being Human, and 13 Reasons Why. On the big screen, he is recognized for his memorable roles in cult classics and acclaimed dramas, including The Big Lebowski, National Treasure, and Capote. Beyond acting, he is a dedicated educator, teaching the Meisner technique at Playhouse West in Los Angeles. He has been married to director and acting coach Tracy Pellegrino (née Bell) since 2008, and he is a stepfather to her two children.