Caustic Deluge

You summon gushes of thick, foul ooze from the Swamp of Oblivion to bubble up and rain down on a cylinder with a 20-foot- radius that is 40 feet tall, centered on a point you can see within range. Each creature in that area when you cast the spell must make a Dexterity saving throw. On a failed save, a creature takes 6d4 acid damage and another 6d4 acid damage at the start of its next turn. On a successful save, a creature takes half the initial damage and no damage at the start of its next turn.

Ooze lingers in the area until the end of your next turn, turning the ground into difficult terrain. When a creature walks into or within the area while it is difficult terrain, it takes 2d4 acid damage for every 5 feet it travels

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the initial damage increases by 1d4 and the radius of the cylinder increases by 5 ft. for each slot level above 4th.