One of Elden Ring's recurring bosses can be traced all the way back to a mysterious Dark Souls 3 file which went unused back in 2016.
As Dark Souls sleuth Zullie the Witch explained in a recent video, Dark Souls 3's files contained data on a "SnakeSoul" monster that never actually appeared in-game, though it did have tenuous connections to the Pus of Man that you fight at the start of the game. With the release of Elden Ring, a match for this unseen boss has finally been found: the Ulcerated Tree Spirit that you fight several times throughout the Lands Between.
Zullie notes that the AI name for the tree spirit is also SnakeSoul, and its in-game model also has some overlap with the Pus of Man, most notably its claws. They also reckon it may have first appeared in some of the earliest leaked artwork for Dark Souls 3, which featured a prickly serpent not unlike the tree spirit we know today.
The Ulcerated Tree Spirits serve as both dungeon bosses and open-world mid-bosses in Elden Ring. They pop up everywhere from Leyndell to the Haligtree, and while they can be annoying to fight due to their status ailments and devastating grab attacks, finding one is usually a stroke of good luck since they often drop the Golden Seeds used to upgrade your healing flasks.
Zullie the Witch also contributed to the file deep-dive which proved that the strongest enemy in Elden Ring is a bugged blood dog which can insta-kill anything.
