Just read his Wikipedia entry. Uh... Wooooow.
In his book The Art of Dreaming, Castaneda describes an encounter during a lucid dreaming session with a supposed conscious entity that was trapped by other inorganic beings. The trapped entity was named the Blue Scout because its "energy" appeared blueish and it was an energetic scout (meaning it was outside of its original realm). The Blue Scout was apparently bait used by the inorganic beings to trap Castaneda as well. But instead they (Castaneda and the Blue Scout) escaped by supposedly merging their energies.The alleged result of merging their energies was that the Blue Scout followed Castaneda to our world. Furthermore, Castaneda claimed that he gave the Blue Scout a human physical body by helping Carol Tiggs give normal birth to her.
A real girl was brought forward at various public sessions held by Castaneda and Tiggs and was introduced as the Blue Scout, and Tiggs was referenced as her mother. This is strange because that girl was someone named Patricia Partin who had real, known biological parents other than Castaneda and Tiggs.
The remains of Partin, sometimes referred to by Castaneda as Blue Scout, Nury Alexander and/or Claude, were found in 2003 near where her abandoned car had been discovered a few weeks after Castaneda's death in 1998, on the edge of Death Valley. Her remains were in a condition requiring DNA identification, which was made in 2006.[2]