Alexander Skarsgård will play Randall Flagg, aka the Dark Man, the Tall Man, or the Walkin' Dude. The embodiment of evil, Flagg is a demonic character with awful powers bent solely on causing chaos, destruction, and death. Able to shift his appearance between human, demon, and various animals, it's implied that he's lived through several eras. The polar opposite of Mother Abagail's character, Flagg leads a community of "evil" plague survivors who help him cause mayhem throughout the series.