The Mushroom Crown is one of the more interesting armor pieces you can find in the Lands Between. Similar to the regular Mushroom Headgear, the Mushroom Crown features mushrooms growing from your character’s head. What makes them different is that the Mushroom Crown increases your attack power when something nearby is suffering from Scarlet Blight or Poison. Here’s where to find the Mushroom Crown in Elden Ring.
To find this piece of armor, you must first make your way to the Lake of Rot. To reach this area you have to go to Nokstella. You will automatically go to this area during Ranni’s quest line, or you can take the coffin down the waterfall in Deeproot Depths. The elevator that leads to the Lake of Rot is near Nokstella, Eternal City Site of Grace. Once you reach the Lake of Blight, make sure you prepare some preservative boluses that will help you survive the Scarlet Blight.
From the Lake of Rot Shoreside Site of Grace, you must travel to the southeast corner of the lake. Along the way, be sure to stop at the decaying obelisks and step on the pressure plates to raise platforms you can walk on. In the corner of the lake, you’ll find a fallen pillar behind a stone structure. Go up the pillar and jump to the next pillar to get onto the stone structure. In the center of the stone structure you will see a pillar with an item on it. The item on the pillar is the mushroom crown.
https://www.gamepur.com/guides/where-to-find-the-mushroom-crown-in-elden-ring Where to find the Mushroom Crown in Elden Ring?