Rimeward

Your bond with the elemental forces allows you to shape them into a shield of formidable defense. You learn the shillelagh  spell, if you do not already know it. When you cast this spell, you can expend a use of your Wild Shape to additionally touch a source of water of at least 1 cubic foot.  You transmute the liquid into an icey shell that acts a shield that you can wear and are proficient with. While wielding the shield, your AC is equal 12 to plus your Dexterity modifier plus your Constitution modifier if you are not wearing heavy armor, and attacks you make with melee weapons while wielding the shield deal bonus cold damage equal to your spellcasting ability modifier.

In addition, you can use your reaction to absorb some of a blow that hits you. When you do so, you may roll 1d8 and reduce any bludgeoning, piercing, or slashing damage you would take from the triggering attack or effect. 

When your shillelagh spell ends, you can harmlessly shake off the frost and ice, but the water evaporates. Once you use this ability, you cannot use it again until you complete a short or long rest.