Align fang makes a creature's natural weapons good-, evil-, lawful-, or chaotic-aligned, as you choose.
A natural weapon that is aligned can overcome the damage reduction of certain creatures, usually outsiders of the opposite alignment.
This spell has no effect on a natural weapon that is already treated as being aligned, such as the claw or bite attack of most demons.
You can't cast this spell on a manufactured weapon, such as a sword.
When you cast this spell to make a natural weapon good-, evil-, lawful-, or chaotic-aligned, align weapon is a good, evil, lawful, or chaotic spell, respectively.