Putrescent Faerie Circle

You create a 20-foot-diameter circle of loosely-packed toadstools that spew sickly white spores and ooze a tarry substance. At the start of each of your turns, each creature within the circle must make a Constitution saving throw. A creature takes 4d8 necrotic damage on a failed save, or half as much damage on a successful one. If a creature attempts to pass through the ring of toadstools, the toadstools release a cloud of spores, and the creature must make a Constitution saving throw. On a failure, the creature takes 8d8 poison damage and is poisoned for 1 minute. On a success, the creature takes half as much damage and isn't poisoned. While a creature is poisoned, it is paralyzed. It can attempt a new Constitution saving throw at the end of each of its turns to remove the paralyzed condition (but not the poisoned condition).