Curthakul's Aura of Vitriol

Toxic energy radiates from you in an aura with a 30 ft. radius. Until the spell ends, the aura moves with you, centered on you. When a creature enters the aura, or starts its turn there, it must make a Constitution saving throw or take 2d6 poison damage and is poisoned for 1 minute. The creature can repeat the saving throw at the start of each of its turns, so long as it is outside the aura.