I found a huge one once while on a hike. I regret not picking it and trying it. It typically grows beneath evergreen trees, that's why it appears in so many Christmas illustrations. There is also a theory that this mushroom is the reason for santa's red & white costume, and that this was the origin of the practice of placing gifts under a tree at Christmas. The 'gift' of the hallucination was knowledge, and perhaps even visions of god(s), since it's use predates Christianity.