Arterial Strike: (Complete Warrior p96)
Requip: Sneak Attack ability, Base Attack Bonus +4
On a successful Sneak Attack, you may reduce the Sneak Attack dice by 1d6 to cause a wound that bleeds for 1 hit-point per round. The wound continues to bleed until it is magically healed or successfully bandaged by a Heal check vs. DC 15. Multiple bleeding wounds stack.
Hamstring: (Complete Warrior p100)
Requip: Sneak Attack ability, Base Attack Bonus +4
On a successful Sneak Attack, you may reduce the Sneak Attack dice by 2d6 to damage your opponent’s legs, which reduces its movement by half. A creature with 4 legs requires two Hamstring attacks to have its movement impaired. Creatures with more than 4 legs are immune to this effect, as are those immune to sneak attacks. The movement reduction lasts until it is magically healed, successfully bandaged by a Heal check vs. DC 15, or 24 hours pass. This ability may be used one per round.