In Aztec mythology, Xolotl was the god with associations to both lightning and death.
He was associated with the sunset and would guard the Sun as it traveled through the underworld every night. Dogs were associated with Xolotl.
This deity and a dog were believed to lead the soul on its journey to the underworld. He was commonly depicted as a monstrous dog. He was also god of twins, monsters, misfortune, sickness and deformities.
Xolotl is the canine brother and twin of Quetzalcoatl, the pair being sons of the virgin Coatlicue. He is the dark personification of Venus, the evening star, and was associated with heavenly fire.