You can use your chelipeds as an extra hand.
Prerequisites: Dex 13, Weapon Focus (claws), heikegani.
Benefit: By using both of your chelipeds together, you can emulate one extra arm. You can wield an addition weapon with this virtual arm, but only one hand is its primary hand, and all others are off hands. You can also use this “hand” for other purposes that require a free hand.