Your martial training makes full use of your natural weapons in unarmed combat.
Prerequisites: Base attack bonus +5, Improved Unarmed Strike, claw or slam attack.
Benefit: When you make an unarmed strike or grapple check to deal damage, you may add your claw or slam damage to your unarmed strike or grapple damage.
Special: A fighter may select Beast Strike as a fighter bonus feat.
Source: Dragon Magazine #355 (Page 76)