The Scadutree Avatar is just one of the optional bosses in Elden Ring: Shadow of the Erdtree, though the area it resides in is pretty hidden, especially if you're not accustomed to exploring thoroughly. This three-phase boss isn't as difficult as some, but it can still be tricky if you haven't collected enough Scadutree Fragments to power yourself up in the Land of Shadow.
Whether you're looking for some help defeating the Scadutree Avatar or you've heard about this optional boss but aren't sure where to find it, help is at hand.