forest oracle
I came across what i thought was a bug, but ended up being a hidden foe in Dale Family Tomb in the north east of Hogwarts Valley over by where you find the Snidget sanctuary. Its a place you can find on your own or by doing a quest for Samantha Dale where her brother gets cursed to where his feet turned into beets, its called "Beeting a Curse" in which she will send you there to pick up an artifact which will help lift the curse, but there is also an Infamous Troll that isnt named in any guide that ive seen online whilst searching for an answer to what i thought was a bug.
Ps, also it could be Aleksandras Troll or The Grim and White Wolf too, even Brigbok (i think thats his name) he is in a lower part of the mine during the quest "Lodgoks Loyalty.
Hope this helps someone 🤷🏻♂️