Armor Of Thorns

Armor (light or medium armor), uncommon

This armor is decorated with small, metal spikes. While wearing this armor, when a creature within 5 feet of you hits you with a melee attack, you can use your
reaction to deal 2d4 magic piercing damage to them, as magical purple spikes pulse from the metal ones.

The breastplate and shoulder protectors of this armor are made of leather that has been stiffened by being boiled in oil. The rest of the armor is made of softer and more flexible materials.