A creature with three or more hands can fight with a weapon in each hand. The creature can make one extra attack each round with each extra weapon.
Prerequisites: Dex 13, three or more hands.
Benefit: Penalties for fighting with multiple weapons are reduced by 2 with the primary hand and reduced by 6 with off hands.
Normal: A creature without this feat takes a –6 penalty on attacks made with its primary hand and a –10 penalty on attacks made with its off hands. (It has one primary hand, and all the others are off hands.) See Two-Weapon Fighting.
Special: This feat replaces the Two-Weapon Fighting feat for creatures with more than two arms.
Source: Monster Manual (version 3.5), page 304.