Serpent’s Scales

Armor (scale mail), rare (requires attunement)

While wearing this armor made from the skin of a giant snake, you gain a +1 bonus to AC, and you have resistance to poison damage.

While wearing the armor, you can use an action to cast polymorph on yourself, transforming into a giant poisonous snake. While you are in the form of a snake, you retain your Intelligence, Wisdom, and Charisma scores. In addition, you don’t need to maintain concentration on the spell, and the transformation lasts for 1 hour, until you use a bonus action to revert to your normal form, or until you drop to 0 hit points or die. The armor can’t be used this way again until the next dawn.