Acid Rain

Acid rain begins falling within a 40-foot-radius, 60-foot-high cylinder centered on a point you choose within range. When a creature moves into the spell's area for the first time on a turn or starts its turn there, the creature must succeed on a Dexterity saving throw or take 8d4 acid damage, and becomes covered in acid. A creature takes 2d4 acid damage if it ends its turn while covered with acid.

A creature can clear the acid with an action.