Potion of Poison

This concoction resembles a potion of healing. But it is actually poison masked by illusion magic. An identify spell reveals its true nature. If drunk, take 3d6 poison damage and make a DC 13 Constitution saving throw or be poisoned. At the start of each of your turns while you are poisoned, you take 3d6 poison damage. At the end of each of your turns, you can repeat the saving throw. On a successful save, the poison damage decreases by 1d6. The poison ends when the damage decreases to 0.