Snapping Teeth

By means of this spell, the caster causes a set of teeth to appear on a person or object; the teeth appear in the exact location touched by the caster. The snapping teeth are contained in a mouth-like orifice about 6 inches in diameter and are capable of snapping at victims within 1 foot. A person or creature with the snapping teeth can cause them to snap at will, effectively giving him an extra attack per round. A normal attack roll is made, and a successful hit inflicts 1-4 hit points of damage.
Note that the victim must be within range of the teeth and that normal facing considerations must be accounted for (for instance, snapping teeth in the back of a person's head can only attack victims that are behind the person).
Snapping teeth can also be placed on a non-living object, such as a tree or a door, In such cases, the snapping teeth are invisible until they make an attack. The snapping teeth will attack any victim that comes within 1 foot; they attack as a 4 HD monster, and each successful hit causes 1-4 hit points of damage. These attacks are automatic and are not controlled by the caster.
Attacks cannot be directed against the snapping teeth, but dispel magic causes them to vanish.

[Complete Wizard's Handbook]

School: Conjuration, Alteration
Level: 3
Rarity: Uncommon

Range: Touch
Components: V, S, M
Duration: 1 turn/level
Casting Time: 3
Area of Effect: 1 creature or object
Saving Throw: None

Material Components:
a tooth from any carnivorous animal, such as a wolf, shark, or serpent