Aku

Aku was the main antagonist of the series Samurai Jack. Born from a cosmic black mass of darkness, Aku was an evil, shapeshifting demon that has taken over the world and ruled it for countless eons. Throughout the series, he was voiced by Mako Iwamatsu in seasons 1-4, but due to his death in 2006, he was replaced by Greg Baldwin in Season 5.