Amulet of Stoneskin

While wearing this amulet, you can harden your body for one minute as a free action. During this time, you have resistance to non-magical piercing, bludgeoning, and slashing damage that isn't animated, you gain advantage of strength checks and saving throws, and your movement speed is decreased by 10 feet. You can use this ability a number of times equal to your proficiency modifier rounded down (minimum of one) per long rest.