Natural Attacks

[Squider]

Do you guys know anyway to make natural attacks (say, claws and a bite) deal other kinds of dmg, as to overcome DR?

[Epinephrine]

Necklace of Natural Attacks, from Savage Species

[RTGoodman]

Each kind of natural attack automatically overcomes some kinds of DR. A bite, for instance, is considered bludgeoning, piercing, and slashing damage, so it overcomes any DR/slashing, DR/piercing, or DR/bludgeoning. There's a whole list HERE (http://www.d20srd.org/srd/specialAbilities.htm#naturalWeapons) that tells what damage type each kind of natural attack is.

For more exotic DRs, Epinephrine is right. Levels in the Monk class and maybe certain other classes let you overcome DR/magic and others, and some prestige classes (Kensai) and items (Amulet of Mighty Fists, I think) let you enchant your natural attacks so they can overcome DR/good and similar DRs.

[Heliomance]

Polymorph Any Object also works.

[23minds]

Druid/Ranger spell align fang (optionally greater) might work. Spell Compendium.

[Quirinus_Obsidian]

Necklace of natural attacks with the Metalline property, 'tis a +1 cost I believe. (Underdark book?)
Can overcome DR of silver, cold iron, and adamantine (needs clarifications)

[ChaosDefender24]

and then ultimately the transmuting property...