A creature with this special attack gains extra natural attacks when it grapples its foe.
If a creature hits with both claw attacks, it latches onto the opponent’s body and tears the flesh.
A creature with this special attack can crush an opponent, dealing bludgeoning damage, after making a successful grapple check.
What is stated above seems very straight forward, and for the most part it is.
A player wanted to take Improved Natural Attack: [Rend]. I told him that Rend is just the damage of two claw attacks and 1.5 x strength modifier and that Improved Natural Attack: [Claw] will indirectly increase the damage of Rend. He then pointed out that with Black Blood Cultist's:
Savage Grapple: Starting at 8th level, you deal damage as if you had hit with all your natural weapons (including rend, if you are raging) on a successful grapple check.
(emphasis: italic) and he was advocating that implies that Rend is a separate natural attack. I told him, "Okay, it is a separate natural attack, but it isn't a separate natural weapon. He then replied, "Well, the feat says Improved Natural Attack, not Improved Natural Weapon." A little stumped, I told everyone to take a 'smoke break.' After thinking about it, I allowed it after determining that there are much more powerful feats he could have taken, and it wouldn't be game-breaking.
Now, Improved Natural Attack states:
Choose one of the creature’s natural attack forms. The damage for this natural weapon increases by one step, as if the creature’s size had increased by one category: 1d2, 1d3, 1d4, 1d6, 1d8, 2d6, 3d6, 4d6, 6d6, 8d6, 12d6.
A weapon or attack that deals 1d10 points of damage increases as follows: 1d10, 2d8, 3d8, 4d8, 6d8, 8d8, 12d8.
This feat may be taken multiple times, but each time it applies to a different natural attack.
There are a few inconsistencies within the text of the feat that is now confusing me a little. It says "Choose one of the creature's natural attack forms." Rend would indeed be a natural attack form (wouldn't it?). But then it says right after it, "the damage for this natural weapon [...]," Rend isn't listed under the 'types' of natural weapons in the SRD:
Natural weapons have types just as other weapons do. The most common are summarized below.
Bite: The creature attacks with its mouth, dealing piercing, slashing, and bludgeoning damage.
Claw or Talon: The creature rips with a sharp appendage, dealing piercing and slashing damage.
Gore: The creature spears the opponent with an antler, horn, or similar appendage, dealing piercing damage.
Slap or Slam: The creature batters opponents with an appendage, dealing bludgeoning damage.
Sting: The creature stabs with a stinger, dealing piercing damage. Sting attacks usually deal damage from poison in addition to hit point damage.
Tentacle: The creature flails at opponents with a powerful tentacle, dealing bludgeoning (and sometimes slashing) damage.
Once again, here lies a conundrum by stating "The most common are summarized below."
- Are Rake, Rend, or Constrict 'uncommon' natural weapons?
- Could one indeed take Improved Natural Attack: [Rend] (et al.)?