Coming up in my game my players are going to be striking through the wildnerness and I wanted to throw in a Monestary along the way that they get tricked into staying at. The monks there will actually be werewolves and will attempt to slay the players in the night (They will be lawful evil rather than CE due to the intense dicipline they had previously in life). I was wondering what the general rule is when a player who started as a Human Monk using unarmed strike later gets a natural weapon (claw) attack (Let's say through Lycanthropy). Should I count the unarmed strike damage as one size category larger?
The general rule places the monks unarmed strike attacks apart from natural weapons such as claws, though potentialy could make the natural attacks as off-hand attacks in addition to monk attacks since they do not need to strike with their fists, so you make either natural weapon attacks or monk unarmed strike attacks, though flurry of blows would be imposible to combine those two in any case since natural attacks arent monk weapons.
flavorwise I'd make the claws slashing attacks with the monk damage, just use the best damage, if the damage is the same I'd prolly choose to increase the damage by one step and allow it to be used with flurry unless you add a bite attack then flurry would be impossible.
It all comes down to common sense, just come up with a reasonable CR for them and nobody will have issues.
This was addressed in 3.5 FAQ like this:
Can a monk who has natural weapon attacks (such as a centaur monk) attack unarmed and still use his natural weapons? For example, let’s say he’s a 4th-level monk. Can he use a flurry of blows and attack at +5/+5/+0 unarmed (plus other bonuses) and then at +0/+0 for 2 hooves?
If the creature normally is allowed to make both weapon attacks and natural weapon attacks as part of the same full attack routine, the monk can do the same (making unarmed strikes in place of weapon attacks). Since a centaur can make two hoof attacks in addition to his longsword attack, a centaur monk can make two hoof attacks in addition to his unarmed strike attack (or attacks, depending on his base attack bonus). The monk can’t use his natural weapon attacks as part of a flurry of blows, but he can make natural weapon attacks in addition to his flurry. Such attacks suffer the same –2 penalty as the monk’s flurry attacks in addition to the normal –5 penalty for secondary natural attacks.
An 4th-level centaur monk has a base attack bonus of +7 (+4 from his 4 monstrous humanoid Hit Dice, and +3 from his 8 monk levels). If he performs a flurry of blows, he makes three unarmed strikes, at +5/+5/+0. He can add two hoof attacks at –2/–2 (–5 as secondary weapons, and –2 from the flurry).
Of course this doesn't directly apply to Pathfinder RPG, so I hope this will be clarified in rules.
Coming up in my game my players are going to be striking through the wildnerness and I wanted to throw in a Monestary along the way that they get tricked into staying at. The monks there will actually be werewolves and will attempt to slay the players in the night (They will be lawful evil rather than CE due to the intense dicipline they had previously in life). I was wondering what the general rule is when a player who started as a Human Monk using unarmed strike later gets a natural weapon (claw) attack (Let's say through Lycanthropy). Should I count the unarmed strike damage as one size category larger?Do note that they'd have to be a monastery of 4th level monks and below. Level 5 monks are immune to all diseases, mundane or magical, thanks to purity of body.
However, I would say the damage is the same, just change the damage type, to slashing, taking the greater of the two damages.
They were all natural Lycanthropes, I made them LE rather than CE due to their being raised in a monastic environment following strict monk rules. The encounter was pretty fun, the PCs managed to get out of there without any fighting, thanks to a incredibly successful diplomacy role by the rogue towards the Head Monk, Master Ling-Ling Long.