Hun Hunahpu (pronounced [hunhunaxˈpu]), or 'Head-Apu I' (a calendrical name) is a figure in Mayan mythology. According to Popol Vuh he was the father of the Maya Hero Twins, Head-Apu and Xbalanque. As their shared calendrical day name suggests, Head-Apu I was the father of Head-Apu. He is believed to be the father of the twins' half-brothers and the patrons of artisans and writers, Hun-Chowen and Hun-Batz. Head-Apu I is paired with his brother, Vucub-Hunahpu, Head-Apu VII. The brothers were tricked in the Dark House by the lords of the Underworld (Xibalba) and sacrificed. Head-Apu I's head was suspended in a trophy tree and changed to a calabash. Its saliva (i.e., the juice of the calabash) impregnated Xquic, a daughter of one of the lords of Xibalba. She fled the Underworld and conceived the Twins. After defeating the Underworld lords, the twins recovered the remains of their father and their father's brother, but could not resuscitate them.
It has been asserted that the Mayas of the Classical Period took a more optimistic view and believed the sad paternal figure to have been reborn as maize. In this theory, the scene of the Tonsured Maize God rising from a turtle carapace (the 'tomb' of the earth) is interpreted as Head-Apu I resurrected. The flanking Hero Twins assisting him are accordingly taken to be his sons. Head-Apu I is thus often referred to as a 'maize deity,' and the maize deity is commonly referred to as a 'first father'. In support of the Maize Deity theory, reference is often made to a pottery scene showing a cacao tree assimilated to the Tonsured Maize God. It has a trophy head suspended among its branches. The trophy head is taken to be that of Head-Apu I while the head of the Tonsured Maize God is its transformation.
The identification of Head-Apu I with the Classic Mayan Maize Deity has become popular, but requires further corroboration. The hieroglyphic name of the Tonsured Maize God (although including the prefix 'One') is not recognizable as that of Head-Apu I. Moreover, the tree with the suspended trophy head is a personified cacao tree, rather than a calabash tree, as in Popol Vuh.