Fly agaric, known scientifically as Amanita muscaria, is a red, white-spotted mushroom found in forests across Europe, Asia, and North America, typically growing in association with birch, pine, or spruce trees and long linked in folklore with fairies and woodland spirits. Its name derives from its historical use as a fly poison, where pieces were placed in milk or other liquids to attract and kill insects. Young specimens are dome-shaped because the cap remains enclosed, while mature ones flatten as the cap expands to expose the gills beneath.