Ran into this beast as level 8, and holy crap that was a fight and a half! Truly did remind me of running into a certain red dragon in Baldur's Gate for the first time :)
Struggled to kill it for a little while too, and it kinda looked like the animation bugged out. Thankfully I had noticed it had a weakness to cold iron, and we had a +1 cold iron dagger in the bag, which was enough to kill it.
Poor Amiri perma died because she had Death's Door going into the fight. Glad we had a Raise Dead scroll, because I didn't want to repeat that fight as it was such a close call.
Horrible loot though :(