The toadstool most associated with faerie is the red Fly Agaric(Amanita Muscaria). This is a toadstool with poisonous hallucinogenic properties. The Vikings ate this magic fungus to gain their fighting frenzy known as "Berserk".
In viking mythology Woton was once chased by devils and the red flecks of foam falling from the mouth of his galloping, six-limbed steed, Slepnir, were magically transformed into red toadstools. Fly Agaric was thus a gift from the Gods. The Celts had a taboo on the red toadstools and, indeed, on many red foods like rowanberries and red nuts and fruits. These were the food of the Gods.

Similarly Robert Graves considers that Amanita Muscaria is in fact the nectar and ambrosia of the Greek Gods, a statement that is reinforced by similar attribution and use of the sacred mushrooms by peoples as far apart as Siberia, Mexico and Borneo. Extracts from the Fly Agaric induce in the partakers great animation during which they dance wildly, have visions and talk to invisible people. What better mushroom to be a magic faerie seat or a gateway to faerieland.

Faerie has claimed many toadstools as its particular property as reflected in names such as Yellow Fairy Club, Slender Elf Cap, Dune Pixie-Hood and Dryad's Saddle.