The Man in Black (but also called "The Smoke Monster" or simply "The Monster" by the main characters) is the main antagonist on the American ABC television series Lost.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.Smoke Monster, a living cloud of black smoke. As the smoke, he could manifest himself as deceased individuals. Manipulative, dangerous, deadly. 