Rake

A creature with this special attack gains extra natural attacks under certain conditions, typically when it grapples its foe. In addition to the options available to all grapplers, a monster with the rake ability gains two free claw attacks that it can use only against a grappled foe. The bonus and damage caused by these attacks is included in the creature's description. A monster with the rake ability must begin its turn already grappling to use its rake—it can't begin a grapple and rake in the same turn.