Which Aztec day sign is represented by a crocodile?

Cipactli is the Aztec day sign represented by a crocodile or caiman. It was the first sign in the 260-day ritual divinatory calendar, the tonalpohualli, which combined 20 named day signs with numbers from 1 through 13.

Cipactli was more than a calendar symbol. In Aztec creation mythology, it was a primeval sea monster with crocodilian, fishlike, and amphibian features. The creature was described as perpetually hungry, with an extra mouth at every joint. Tezcatlipoca and Quetzalcoatl battled it and used its body to form the earth, making Cipactli a mythic foundation for the world.

Because the creature emerged from primordial waters and became the earth, the crocodile sign could represent beginnings, fertility, and the physical ground beneath human life. Some traditions also associate Cipactli with a flood survivor who helped repopulate the world. A common mistake is to treat the sign as merely an ordinary animal symbol; in Aztec thought, it referred simultaneously to a calendar day, a cosmic monster, and the earth’s formation.