*Necromancer is the penultimate boss of Castle Crashers and one of the 31 Playable Characters. His magical attacks are Non-Elemental and his starting weapon is the Evil Sword. The Necromancer has glowing red eyes and dark gray armor. He wears a helmet that has vertical breaths that extend to the bottom of the visor, visible battle damage including a couple of scratches on his portrait, and horns. The Necromancer first appears flying above the lava river in Lava World alongside the Evil Wizard, possibly on their way to resurrect the Cyclops. Taking notice of the player, the Necromancer stops and raises a small army of Skeletonss to keep them occupied, before flying away. After arriving at the Cyclops' grave site, the Necromancer uses his dark magic to revive him and turn him into the Undead Cyclops.

Much later in the game, the Necromancer, once again accompanied by the Evil Wizard, is seen in the Marsh level. He uses his dark magic to revive more skeletons, but this time, the Evil Wizard turns half of them beefy. The Necromancer's final appearance is in his own sublevel, Necromancer's Room, where he resurrects a whole army made up of various kinds of enemies to fight for him.

Upon defeat, he will fly up into the air out of sight. Shortly after, he will drop his weapon, the Evil Sword. The player can then exit the room to destroy another large purple crystal, and be able to progress to the final boss: the Evil Wizard in the Final Battle level.*