Tlazolteotl, the Filth Eater or Filth Goddess, is an Aztec earth and mother goddess whose worship the Aztecs traced to the Huastec region of the Gulf coast, and she gathers together a striking range of domains: sexual desire and transgression, childbirth, and above all purification. Her name comes from tlazolli, meaning refuse, filth, or by extension moral filth and misconduct, especially of a sexual kind, and her paradoxical nature is that she both provokes vice and consumes it, she is the goddess who kindles illicit desire and the goddess who cleanses its stain. This double role is expressed in a remarkable ritual institution reported in the colonial sources.
A person burdened by sexual transgressions could, characteristically once in a lifetime and often in old age, make a confession of them before a priest of Tlazolteotl; the goddess was believed to eat the filth confessed, taking the moral defilement into herself and so cleansing the penitent, who was thereby freed of the fault and its consequences. She is associated with spinning and weaving and with raw cotton, which appears in her headdress, and she is often shown with a band of unspun cotton and spindles, and sometimes with black around the mouth, the filth she has consumed. As a mother goddess she also presided over childbirth and was invoked by midwives. Tlazolteotl embodies an idea found in a number of Mesoamerican deities: that the same divine power which governs the dangerous, disorderly and polluting forces of life is also the power that can purify and set right, so that the eater of filth is at once the source of transgression and the means of absolution from it.