One Hunahpu, son of the primordial elders Xpiyacoc and Xmukane, is a ballplayer god whose story frames the central drama of the Popol Vuh. With his brother Seven Hunahpu he disturbs the lords of the underworld with the noise of their game and is summoned down into Xibalba, where both are defeated by trickery, sacrificed, and buried; One Hunahpu's severed head is hung in a calabash tree. When the underworld maiden Xquic approaches, the skull spits into her palm and so begets the Hero Twins, ensuring the eventual defeat of the death lords. Iconographic and epigraphic study identifies One Hunahpu with the Classic Maya maize god, whose decapitation and regeneration mirror the planting and sprouting of maize.