Perhaps the game has a bold reference to Jojo. But that's my opinion. (Bloodstained: Ritual of the Night)

And it's a stone mask. Cosmetic accessory made in a similar style. However, there are differences: 1)though the lips of two identical masks, the masks in the game no fangs. 2) Instead of the curls on his forehead, the stone masks from the game in the middle of the forehead grows a horn. Not long, but, remembering who created the stone mask in jojo, it can also be considered a reference. 4) In the mask from the game to the horns diverge schematically shows cracks or zigzags, I do not know, in General, on the forehead of her here is such a pattern.
The stats mask sewn 1, luck 1, mind 1, body 1.
The description says Stone mask, which the tribe used in the sacrifice.
Personally, I mask fell from the bone nagita right at the exit of the asylum. Wanted to go to the portal, and then there's the loot drops, the beauty.
In General, the category will be updated, and maybe I did make a screenshot. Maybe.