Acid Fog(Player's Handbook v.3.5, p. 196)
Conjuration (Creation) [Acid]
Level: Sorcerer 6, Wizard 6, Warmage 6, Blighter 6, Sha'ir 6, Death Master 6, Dread Necromancer 6, Water 7,
Components: V, S, M, DF,
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Effect: Fog spreads in 20-ft. radius, 20 ft. high
Duration: 1 round/level
Saving Throw: None
Spell Resistance: No
Acid fog creates a billowing mass of misty vapors similar to that produced by a solid fog spell (page 281). In addition to slowing creatures down and obscuring sight, this spell's vapors are highly acidic. Each round on your turn, starting when you cast the spell, the fog deals 2d6 points of acid damage to each creature and object within it.
Arcane Material Component: A pinch of dried, powdered peas combined with powdered animal hoof.