Nonlethal damage with natural weapon?

[Yorae]

Is there a way to deal nonlethal damage using a natural weapon (in either 3.5 or PF)?

I'd love for my animal companion to use the Enforcer feat (free intimidate on melee attack).

[Baroncognito]

Any weapon can do nonlethal damage with a -4 penalty to hit.

Bludgeoner is a feat that allows you to do nonlethal damage with a lethal bludgeoning weapon without the -4 penalty.

Merciful is a weapon enhancement that can be used on an amulent of Mighty fists, it's a +1 bonus, and it allows you to do nonlethal damage with a lethal weapon without the -4 penalty.

[gorfnab]

Subduing Strike feat - Book of Exalted Deeds