The first time you have encountered an Ulcerated Tree Spirit in Elden Ring is most likely at Fringefolk Hero's Grave, located in one of the very first areas in the game. Since then, there have been more variations of the Ulcerated Tree Spirit in various spots in The Lands Between, and they are just as violent as they are chaotic.
Related: Elden Ring: How To Defeat Leonine Misbegotten
FromSoftware embodies what it is like to battle a relentless, endlessly wriggling worm whose bent on killing you. Their sheer aggressiveness and speed in combat make it doubtlessly challenging to keep up with them, much less defeat them. As such, a fully detailed rundown of these parasitic worms is to permanently exterminate them.
Aside from the ones you'll find in Fringefolk Hero's Grave and War-Dead Catacombs in Limgrave and Caelid respectively, Ulcerated Tree Spirit bosses can also be found at Mount Gelmir and the Mountaintops of the Giants. For the former, you'll find the boss at the base of a Minor Erdtree near the Road of Iniquity Site of Grace, while the latter is close to Giant-Conquering Hero's Grave.
With similar move sets, the game has allowed you to call for as much help as you need when it comes to these bosses. It is best to summon tanky Spirit Ashes such as Lhutel the Headless or Kaiden Mercenary to deal with the walloping these Ulcerated Tree Spirits inflict. With the Mount Gelmir boss, you can do combat on horseback, which makes it easier to evade during devastating AoE attacks. But the Ulcerated Tree Spirit in the catacombs puts you in a bit of a tough spot since you're not given an open space to manoeuvre, though that doesn't mean it isn't doable.
For a wriggling worm, the Ulcerated Tree Spirit has a vast panoply of
Read more on thegamer.com