Amanita Muscaria in your picture isn't exactly dangerous persay it just depends on who eats it and why. The vikings used to use it dried as a form of currency and many credit its use with being part of the origins of Father Christmas.
I love the faeries name too my friend and a great little folk tale non the less.
Oh! Thank you for the input! I don't have any knowledge on fungi, I just read about the fairy rings and thought I shoud write a children's story about it.
The viking-coin thing...wow! I didn't know that!