Amanita muscaria is a striking red mushroom with white spots. It is the classic fairy tale toadstool, with connections to Alice in Wonderland, Nintendo video games, and Smurf villages. Some were also seen dancing in Fantasia (1940).
Amanita muscaria can be found all over the world, often sprouting below pine, spruce, fir, birch, and cedar trees, and is generally considered to be poisonous. (It’s been used as an insecticide.) If you happen upon some, do not eat them, but do learn more about them!
Check out the North American Mycological Association’s Instructional Materials for Teachers and Naturalists – Teaching About Fungi: Grades K-12 and College, which includes this useful-looking pdf: The Fungus Files – An Educator’s Guide to Fungi K-6. You can also grow your own completely edible fungi with Back to the Roots’ Organic Mushroom Farm.