Acid Rain

''A mustard-colored cloud whirls into being. It unleashes a foul-smelling rain accompanied by sizzling noises as it eats through metal, cloth and flesh.''

A toxic shower covers the area of effect. Anything caught beneath the rain takes 4d4 points of acid damage. It is easy to move out of the cube, but if a creature cannot, it continues to take damage for each round spent in the rain. If a creature fails its saving throw, an item it holds could take damage, as if the creature had rolled a natural 1. Unattended objects also take damage from the falling acid. When the spell expires the acid that had rained down instantly evaporates.