Undead Nun
Described in the valley's own bulletin. No stat table ships for it.
From Coen's journal
Something horrible happened at Saint Tyna's. It covered the woods with thick fog and revived the nuns killed by the plague. Even when struck down and seemingly killed, they rise again, raging with fury. Stripped of any trace of their humanity, they have transformed into unkillable, undead monsters, unable to find eternal peace.