In Aztec mythology, Copil was the son of the goddess Malinalxochitl and Malinalco king, Chimalcuauhtli.[1]
When grown he sought revenge for his mother's abandonment by her brother, Huītzilōpōchtli. When the Mexica were encamped at Chapultepec, he confronted his uncle. Hostility brewed, and Copil was killed[1] on the hill Peñón de los Baños by Mexicas under orders of Huītzilōpōchtli,[2] while Copil was awaiting to watch the battle between the Mexicas and tribes he incited to fight them.[3] He was slain by priest Cuauhtlequetzqui, who later married Copil's daughter, Xicomoyahual.[4] He was decapitated and his head was placed atop the hill and then an outcrop in Lake Texcoco.[5] His heart was extracted and thrown into the swamp where it grew into nopal. It was here the Mexicas were given the signal to build Tenochitlan.[3][5]