Xolotl

In Aztec mythology, Xolotl (pronounced in Nahuatl) was the god with associations to both lightning and death.Although often depicted in relation to the underworld, Xolotl was not a psychopomp in the Western sense. Xolotl did, however, aid the dead on their journey to Mictlan, the afterlife in some myths.Xolotl was also the god of fire and of bad luck. He was the twin of Quetzalcoatl, the pair being sons of the virgin Coatlicue, and was the evil personification of Venus, the evening star. He guarded the sun when it went through the underworld at night. He also brought forth humankind and fire from the underworld.
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[Aztec] In Aztec and Toltec mythology, Xolotl is the god of lightning who guides the dead to the Mictlan. The Aztec regard him as the twin brother of Quetzalcoatl. As lord of the evening star and personification of Venus, he pushes the sun at sunset towards the ocean and guards her during the night on her dangerous journey through the underworld. Xolotl is represented as a skeleton, or as a man with the head of a dog.