Xolotl is the Mexica god of lightning, twins, monsters and the evening, the canine-headed companion and twin of Quetzalcoatl. Where Quetzalcoatl is the planet Venus as the morning star, Xolotl is Venus as the evening star that sinks into the underworld, and he serves as a psychopomp, guiding the sun on its nightly passage through the land of the dead. In the myth of the making of the present humankind it is Xolotl, or Quetzalcoatl (the sources vary), who descends to Mictlan to recover the bones of a former race from which people are re-created. His association with the xoloitzcuintli, the native hairless dog buried with the dead to guide them across the underworld's waters, ties him to death and to the dog as companion of souls, and he is linked besides with deformity, the doubled or monstrous, and the ballgame.
Xolotl's clearest surviving image is in the sixteenth-century Codex Telleriano-Remensis, where he is painted as a dog-headed man in bicolour purple and gold, wearing an ear ornament shaped like a claw, a detail the scholar Eloise Quinones Keber reads as marking his association with Quetzalcoatl. On the same folio he also wears a cotton headband with a spindle and thread, an attribute elsewhere linked to the goddess Tlazolteotl, so that a single painted page ties Xolotl's iconography to two quite different deities at once, evidence of how tightly interwoven the underworld, Venus and purification themes of central Mexican religion could become in a single figure's imagery.