Don Juan Matus
Matus is described as a Yaqui Indian to whom Castaneda was first introduced at a bus depot in Yuma, Arizona in the early 1960s. He turns out to be a 'Man of Knowledge' who imparts much of his wisdom and clarity through his 'connection' with Castaneda. The Knowledge is passed on to Castaneda by means of actual experiences, simple exercises and much patience on the part of both which ends in further transforming both characters' view of the world.
Carlos Castaneda never claimed Juan Matus to be a shaman and yet the actual existence of don Juan has been disputed by a handful of critics who claim his practices and beliefs are inconsistent with his alleged identification as a Yaqui shaman. In Journey to Ixtlan, Juan Matus is quoted as saying "No one knows where I am really from or who I am for certain", so in effect the statements in regard to Juan Matus' lineage are not applicable.
In Castaneda 
Regardless of whether don Juan is a fictional character, or an actual human subject of study in Castaneda's books, Juan tells Carlos (the personage representing Castaneda) that he is a brujo (Spanish for sorcerer or medicine man); a sort of healer, sorcerer or shaman, who had inherited (presumably through a lineage of teachers) an ancient Mesoamerican practice for vastly enhancing one's awareness of, and interaction with, the energies of the Earth and its assorted beings.
In the books don Juan was an expert in the cultivation and use of various psychotropic plants (specifically, psychedelic mushrooms, datura and peyote) found in the Mexican deserts. These were used as aids to reach states of non-ordinary reality in the teachings he conveyed to Carlos.
In the books the character of don Juan is presented as an unmarried old man, of Yaqui indigenous ancestry, with great strength and agility, who spoke excellent Spanish but had never been to college, and who apparently had lived his entire life in poor conditions. Don Juan's philosophy might be summed up in a passage from Castaneda's first book, The Teachings of Don Juan: A Yaqui Way of Knowledge:
For me there is only the traveling on the paths that have heart, on any path that may have heart. There I travel, and the only worthwhile challenge for me is to traverse its full length. And there I travel—looking, looking, breathlessly.
Castaneda's books featuring Don Juan Matus 
- The Teachings of Don Juan: A Yaqui Way of Knowledge (1968) ISBN 0-520-21757-8
- A Separate Reality: Further Conversations with Don Juan (1971) ISBN 0-671-73249-8
- Journey to Ixtlan: The Lessons of Don Juan (1972) ISBN 0-671-73246-3
- Tales of Power (1974) ISBN 0-671-73252-8
- The Second Ring of Power (1977) ISBN 0-671-73247-1
- The Eagle's Gift (1981) ISBN 0-671-73251-X
- The Fire from Within (1984) ISBN 0-671-73250-1
- The Power of Silence: Further Lessons of Don Juan (1987) ISBN 0-671-73248-X
- The Art of Dreaming (1993) ISBN 0-06-092554-X
- The Active side of Infinity
- The Wheel of Time
Media featuring Juan Matus 
- "Juan Matus" – a song by Zoos of Berlin, in album "Taxis."
In subsequent works 
In their writings, Taisha Abelar, Florinda Donner and Lujan Matus also included the character of don Juan Matus, although he went by different pseudonyms such as Mariano Aureliano. In all of these books don Juan Matus was a nagual who was the leader of a group of practitioners in the tradition of mystical self-actualization.
See also