Antlers of the Forest Steward

These large antlers are affixed to a sturdy headpiece with runes carved over every inch of them. As an action, you can transform into a giant elk for one hour as if you transformed via polymorph (does not require concentration). This transformation ends early if you use a bonus action to end it or if you are reduced to 0 HP, with any excess damage carrying over to your original form. Once this property is used, it can't be used again until the next dawn. 

Notes: Shapechanging