Regeneration (Ex)
No form of attack deals lethal damage to the tarrasque. The tarrasque regenerates even if it fails a saving throw against a disintegrate spell or a death effect. If the tarrasque fails its save against a spell or effect that would kill it instantly (such as those mentioned above), the spell or effect instead deals nonlethal damage equal to the creature’s full normal hit points +10 (or 868 hp). The tarrasque is immune to effects that produce incurable or bleeding wounds, such as mummy rot, a sword with the wounding special ability, or a clay golem’s cursed wound ability.
The tarrasque can be slain only by raising its nonlethal damage total to its full normal hit points +10 (or 868 hit points) and using a wish or miracle spell to keep it dead.
If the tarrasque loses a limb or body part, the lost portion regrows in 1d6 minutes (the detached piece dies and decays normally). The creature can reattach the severed member instantly by holding it to the stump.