Santa's character is actually based on a shaman enjoying a fly agaric, circulates in various versions. The theory explains the Anglo-American image of Santa’s flying reindeer with fly agaric hallucinations and expands to explain the distribution of gifts to and from December.

The construction and use of fly agaric theory is interesting for the folklorist to follow. It is a myth that defines Christmas in relation to the mythical early-onset tradition of Arctic shamanism and leaves its connections to modern Christmas unclear and symbolic.

The theory is based on the red and white color of Santa's costume and fly agaric, as well as the prevalence of the fly agaric theme, especially in Scandinavian Christmas cards and spruce decorations.

In addition, it is reported that Siberian or Sámi shamans have distributed dried fly mushrooms as gifts during the winter solstice. Because the doorway of the hut or yurt is besieged by snow in the winter, they enter through an opening in the roof - like a chimney.

There is evidence of rituals based on fly agarics in which the shaman dresses as a fly agaric. The theory is also confirmed by Petteri Punakuono's resembling a fly mushroom and Christmas elves as a shaman's auxiliary spirit.

Reindeer are the soul animals of shamans, and consuming a psychoactive fly agaric has made you imagine that both man and reindeer are flying.

The fly agaric theory has been criticized, for example, inaccuracies about Siberian shamanism. It is also noted that the current Santa Claus character with flying reindeer is not ancient but first appeared in Clement Clarke Moore’s poem in 1823.

According to defenders, Moore’s source could have been Northern European mythology, which could include a sleigh and reindeer. After all, god Thor was driving in Flying Wagons pulled by two goats, and Odin, considered one of Santa's role models, flew with his troops in the sky.