The Horned King was the main antagonist of Disney's The Black Cauldron, voiced by John Hurt, who also voices and portrays the Great Dragon in Merlin.He is a treacherous, vindictive, malicious and spiteful monarch who plans to find the Black Cauldron and use its power to unleash an army of deathless warriors called the Cauldron Born. He is Taran's arch-nemesis.