You can pull grappled enemies apart.
Prerequisites: Str 19, Dex 15, constrict ability, Greater Multigrab, improved grab, Multigrab, two constricting members.
Benefit: If you maintain a hold with more than one appendage on an opponent and are able to constrict, you can make an additional rend attack in the same round. This attack automatically deals double the base damage for a constrict attack, and the damage bonus is 1½ times your Strength bonus. However, making this rend attack automatically releases the held creature on its next action. You must reestablish the hold to constrict again.
Source: Savage Species, page 39.