Man in Black.

About Man in Black

The fictional character and the main antagonist on the American ABC television series Lost is most frequently referred to as The Man in Black (but also referred to as "The Smoke Monster" or simply "The Monster" by the main characters). He appeared primarily as a cloud of black smoke until the final episode of season five where he appeared as a middle-aged man dressed in black. In season six, he primarily appeared in the physical form of John Locke (Terry O'Quinn). He exhibited the ability to "scan" the minds and memories of others, allowing him to confront characters such as Mr. Eko (Adewale Akinnuoye-Agbaje) and Ben Linus (Michael Emerson), with "judgment" (a replay of their pasts), and to assume the forms and memories of the deceased, starting with the original Man in Black himself, his brother Jacob (Mark Pellegrino), or Christian Shephard (John Terry), Yemi (Adetokumboh M'Cormack), Alex Rousseau (Tania Raymonde), and Locke. According to Jacob, who explains this to Richard Alpert (Néstor Carbonell), it is the incarnation of evil, and its primary goal—to escape from the island—would be the "end of everything good".