Fangs of the Vampire King(Spell Compendium, p. 88)
Level: Assassin 3, Blackguard 3, Deathbound 3,
Components: V, S,
Casting Time: 1 standard action
Duration: 1 minute/level
Hissing an evil laugh, you sprout sharp fangs to drain the blood of your foes.
You grow vampirelike fangs that allow you to make bite attacks as natural attacks. Your bite attack deals 1d6 points of damage + your strength modifier, and 1 point of Constitution damage. If you make a full attack with other weapons, you can make a bite attack as a natural secondary attack (-5 penalty on the attack roll).