Crown of the Frozen Princewondrous, legendary (requires attunement)

This simple crown made of ice, enchanted to never thaw or crack, is set with rough diamonds and sapphires. This item has 3 charges and regains 1 expended charge each day at dawn.
While attuned to this crown you know the cantrip Frostbite if you did not before, which you can cast as a bonus action; You are also able to cast Armor of Agathys at will, without expending a spell slot. Additionally, as an action you can expend a charge to cast Freezing Sphere, Investiture of Ice, or Wall of Ice, ignoring material components. If you are not a spellcaster you use your Constitution as your spellcasting ability for this item.

crown, hat, helmet