Tails of Akinari

You recite the forbidden true name of Akinari, causing a foul barbed tail to stick out of your backside. Until the spell ends, you gain a prehensile tail that functions as a third hand which can stretch up to 10ft and cannot activate magic items. This tail can carry up to 20 pounds and as a bonus action can make a spell attack against a creature within 10ft and does 2d8 piercing damage on a hit.