Miasma

Create a wall of toxic fumes on a solid surface within range, up to 60 ft. long, 20 ft. high, and 1 ft. thick, or a ring up to 20 ft. in diameter. When it appears, creatures in its area must make a DEX save, taking 8d8 acid damage on a failed save, or half on a success. One side emits fumes; creatures ending within 30 ft. of that side or inside the wall take 8d8 poison damage and must make a CON save or be poisoned for the duration.