Not necessarily....
(And not that I am suggesting anyone tries eating it...)
Commonly called Fly Agaric (Scientific name: Amanita muscaria), the Russians (amongst others) consider it a delicacy.
"Apparently most people eat only the caps or the very young buttons. They must be boiled in a large volume of water for a period of time, and then you need to toss out that water. After that, most cultures will either fry them like normal mushrooms, or pickle them, or preserve them in oil; I happen to know that a certain set of Italians do this. The Japanese around Nagano eat Amanita muscaria as pickles, as do the Lithuanians, Finns and Russians."
(Source: https://honest-food.net/eating-santas-shroom/)
Make sure to toss out the water - it contains toxins that have been leached out of the mushrooms.
It is also hallucinogenic, and is widely considered to have been the hallucinatory ‘shroom responsible for Alice’s trip into Wonderland.
As I said, I wouldn't advise anyone trying this (indeed I considered putting most of the above inside spoiler tags...)