Avian Armor (5e Equipment)
From D&D Wiki
Armor (studded leather), very rare (requires attunement)
This suit of studded leather armor is decorated with large bird's feathers, giving the arms a wing-like appearance. The suit comes with a mask shaped like a bird of prey's head. While wearing this armor you gain a +2 bonus to AC.
You can use your bonus action to speak the command word and polymorph into a giant eagle for 1 hour or until you end the effect with a bonus action. You cannot use this feature again until it recharges at dawn.