Aztec creation accounts, recorded in colonial-era Nahuatl and Spanish sources including the Codex Chimalpopoca's Legend of the Suns and Bernardino de Sahagun's Florentine Codex, describe the world beginning as an expanse of primeval water on which a single vast monster, Cipactli, floated alone, described variously as combining the features of a crocodile or cayman, a fish and a toad, an intentionally composite and monstrous form. The gods Tezcatlipoca and Quetzalcoatl, in some versions transforming themselves into giant serpents for the task, seized Cipactli from opposite ends and tore the creature's body violently in two, lifting one half up to form the sky and pressing the other half down to become the surface of the earth.
The earth's physical features were then explained as Cipactli's own body, its back forming mountains and hills, its skin the surface soil, its hollows becoming valleys, caves and springs, and its hair the trees, grass and flowers that grow upon it, so that in Aztec thought the ground itself remained, in an ongoing physical sense, the mutilated body of the primordial monster rather than an inert substance shaped from nothing. Some accounts describe Cipactli as needing to be fed with human blood and hearts on a continuing basis in compensation for the violence of the dismemberment, a theme scholars connect to the broader Aztec religious logic that linked the world's continued stability to a debt of blood owed by humans to the forces that had made it.