In Aztec mythology, a Nagual was a totemic spirit; each god and human had a Nagual such as Huitzilopochtli/hummingbird and Quetzalcoatl/feathered serpent.

Nagual is also a term used in the books by Carlos Castaneda to describe a person who is able to lead people to new areas of perception. Also, Nagual can be directly linked to eastern "concept" of Tao or meditation, or simply infinity, but that is only a way to say it, because these "concepts" are outside of our understanding and reason. As Castaneda's teacher says: "we cannot understand the Nagual, we can only see for ourselves that it exists". As opposed to the Nagual stands the Tonal, which can roughly be linked to the concept of Ego.

A Nagual is the benefactor of an apprentice, a sort of guide to total freedom