Ring of Oceiros, former king of Lothric. In his later years, Oceiros became fascinated with dragons. After going mad, he was more commonly known as the Consumed King. Many assassins were dispatched to his domain, but none returned. The Consumed King ascribed his resilience to the divine protection of the dragon scale.

This ring is fashioned from the scale of an ancient, crystalline blue dragon. While you're wearing this magic ring, any critical hit against you becomes a normal hit.

Art Credit: 
Dragonscale Ring by FromSoftware            
Dark Souls