Wall of Bones

This spell causes a wall of bones to erupt from the earth in whatever shape the caster desires within the limits of the area of effect. The wall is a random construction of bones from many types of creatures. The wall need not be vertical. but it must rest upon a firm foundation or it will collapse. Since the wall has many small openings and gaps, it provides only 50 percent cover. Missiles can easily be fired from behind the wall, and creatures of small size (less than 4 feet tall) can wriggle through openings in the wall at the rate of 10 feet per round. However, the wall has many sharp edges and creatures wriggling through it suffer 1-8 hit points of damage per 10 feet traveled.
If the spell is cast in an area occupied by creatures, the wall of bones appears everywhere except where the creatures stand. Creatures in the affected area suffer an immediate 2-16 (2d8) hit points of damage when the wall appears. The wall can be smashed by creatures wielding blunt weapons with a Strength of 18 or greater. Every 10 hit points of damage causes a 5 foot x 5 foot x 6 inch section of the wall to collapse. The wall of bones is unaffected by animate dead.

[Complete Wizard's Handbook]

School: Conjuration/Summoning, Necromancy
Level: 5
Rarity: Uncommon

Range: 60 yards
Components: V, S, M
Duration: 1 turn
Casting Time: 1 round
Area of Effect: 10-foot square/level; 6-inch thickness/level
Saving Throw: None

Material Components:
the branch of a withered tree taken from a cemetery