Venom Bolt

You release a beam of fell enegy from your eye, mouth, fingertip, etc that travels in a 100 feet long and 5 feet wide line in a direction you choose. Each creature in the line must make a Dexterity saving throw. A creature takes 2d8 acid damage and is paralyzed and is paralyzed for 1d4+1 rounds on a failed save, or half as much damage on a successful one. The beam can act as a moving mist and bypass walls so long as they have small holes, narrow openings, and even mere cracks, though it treats liquids as though they were solid surfaces. 

The acid corrodes structures and objects it comes in contact with in the area that aren't being worn or carried.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.

Adapted from 3.5e Serpent Kingdoms sourcebook.