While grappling, you can cut off an opponent’s air and blood supply.
Benefit: While you have an opponent up to one size category larger than you grappled, you can attempt a grapple combat maneuver with a –5 penalty on the check. If you succeed, you have pinned your opponent and hold the opponent in a chokehold. When you maintain the grapple, you also maintain the chokehold. A creature in a chokehold cannot breathe or speak, and thus cannot cast spells that have a verbal component. An opponent you have in a chokehold has to hold his breath or begin suffocating. Any creature that does not breathe, is immune to bleed damage, or is immune to critical hits is immune to the effects of your chokehold. When the grapple is ended, so is the chokehold.