Magic Mushrooms & Reindeer The Origin of the Santa Claus Legend? The hallucinogenic fly agaric mushroom is one of the favorite foods of the arctic circle reindeer (domesticated caribou) in Scandinavia. Reindeer are central to the lives of the indigenous Saami peoples who herd them. The shamanic traditions of the Saami include eating the mushrooms and contacting the "Great Reindeer Spirit." Ingesting fly agaric mushrooms can produce a sensation of flying. It is thought that the 19th century myth of Santa Claus may have its roots in older Saami traditions.