Fly Agaric
(Amanita muscaria)
House Fly
Fly Agaric sculpture by "Wildman"

Fly Agaric, Yellow Variety

sculpture, acrylic paint by "Wildman"

Fly Agaric, Yellow Variety

Fly Agaric, Yellow Variety

Note the characteristic concentric rings on the lower stem.

The fly agaric has a blood red cap (although there's also a yellow-orange subspecies) 2-10 inches wide with faint radial lines toward the margin. Cottony patches stick to its surface.

The broad white gills are crowded together. There's a fragile, white ring on the upper stalk.

Red Fly Agaric

The whitish stem, which sometimes has an enlarged bulb at its base, is circled with concentric ridges toward its base, a very important identification characteristic.

This mushroom is poisonous, but not deadly. The Koryak people, nomadic, shamanistic, Siberian reindeer herders, traditionally used it to hallucinate, although the poisons would leave them quite ill afterwards. Then they'd drink their urine, which contains the hallucinogen, to get high again. When that no longer worked, they'd drown their symptoms in vodka.

The Aztecs would feed the mushroom to their warriors to make them braver.

Aspects of Santa Claus were allegedly inspired by this mushroom. His red coat and white buttons symbolize the red mushroom with its white patches. Santa flies because the mushroom sometimes creates the hallucination of flight. He uses reindeer because they're fond of the mushroom, and herders who eat reindeer that have eaten the mushroom get high too.

The Koryak shaman would bring prepared fly agarics to ceremonies in a sack, like Santa's bag of toys, and enter the yurt (portable circular domed dwelling) through the smoke hole (like a chimney).

Santa lives at the North Pole because for most Europeans, Siberia might as well be the North Pole. And in Europe today, Christmas cards still often depict the fly agaric.

Shaman

Drunk Fly

Santa Claus

Reindeer

Yurt
Yurt

North Pole

The mushroom gets its name because people used to put it in a glass of milk to kill flies. The fly is supposed to drink the milk, get high, fly around in a frenzy, then drop dead in mid-flight. I don't know whether or not this really works.

The fly agaric may well be the legendary soma, praised in the ancient Vedic texts of India.

Fly Over Bowl
It's also the mushroom Alice ate in Lewis Carroll's Through the Looking Glass. One of the hallucinations it causes is to make things look larger, so Alice got smaller and was able to slip under the door.
Alice
In the excellent 1988 nature movie, The Bear, an orphaned bear cub eats this mushroom and experiences an instant replay of the 1960's.
Bear Cub
Note: Although not everyone agrees with this evaluation, I think the North American orange variety of this mushroom usually does not cause hallucinations, it just gets you sick! People who have used it to try to get high rarely try to repeat the experience.
Illness
On the other hand, the Japanese (and others) boil it in 2 changes of salted water, get rid of the toxins, and serve it in restaurants! Whether this will work elsewhere, where there may be different species of this mushroom, is anyone's guess, but I certainly wouldn't risk it when there are so many other safe mushrooms.
Japanese Food