This mystery can be found in southwest Lincolnscire, just north of the Temple of Pluto.
Interact With the Fly Agaric and Defeat the Bears
When you interact with the mushrooms, you’ll immediately enter a hallucinogenic state and you’ll be surrounded by 5 bears. You’ll have to defeat all the bears to complete the mystery.
Although this is one of the simplest fly agaric mysteries, it could also prove to be one of the most difficult if you’re not prepared. If you get caught between the bears in melee range they will tear you up pretty quickly with red rune aura attacks. You should avoid these as much as possible, and take out as many bears as you can with ranged attacks once you’ve created enough distance between yourself and the bears. Using special abilities will leave you vulnerable to being knocked down if the animation takes too long, allowing the bears to charge you while you’re locked in the animation. If you’re out of arrows, try a series of light attacks interspersed with dodges whenever a bear is about to strike. This should allow you to bring down the bears fairly quickly while avoiding their most damaging attacks. Once you’ve killed all the bears, the mystery will complete.