AG Armor Of Agathys AG

A project is magical forest surround you, manifesting as a spectral frost that covers you and your gear. You gain 5 temporary points for the duration. If a creature hits you with a melee attack while you have these points, like creature takes 5 cold damage. 

     Higher levels. When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points in the cold damage increase by 5 for each spell slot level above 1st.