Bonechill is an enemy in Super Paper Mario and the boss of Chapter 7. He is a massive, undead dragon with a large, blue-scaled head, six small, white-feathered wings on his back, and a large golden cannon with two wheels for a lower body. He is the leader of the Skellobit army, and uses ice attacks in combat.
Before the outset of the game, Bonechill was stuck in an unknown prison in The Underwhere along with his army. Count Bleck set him free to defeat Mario (who was the hero of legend as told in the Light Prognosticus), and the presence of Bonechill's Skellobits in Castle Bleck support the idea that they had some sort of affiliation or agreement, although Bonechill claims to be seeking the Pure Heart in order to use its power for himself. Ultimately, Bonechill failed in his attempt to destroy the Heroes of Light and seize control of The Overthere and The Underwhere, as his army was defeated and he himself was shattered to bits by Mario and his companions.