I think the most important FAQ rule in this context is: "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)."
As far as I can tell, the part about being "normally allowed" to make both weapon attacks and natural weapon attacks is a FAQ invention, but even as it stands it makes for some fancy polymorph twinkism.
A cave troll (MM3) has a humanoid form and would normally be allowed to combine it's natural attacks with weapon attacks. (For example, by wielding a greatclub and using its bite as a secondary natural attack.) Since monks can strike with any part of their body as part of a flurry, they don't even have to "waste" a claw attack to hold a weapon. As a result you get a "regular" flurry (with +9 Str bonus) on top of all the cave troll's natural attacks (as secondary attacks).
As far as I can tell, the part about being "normally allowed" to make both weapon attacks and natural weapon attacks is a FAQ invention, but even as it stands it makes for some fancy polymorph twinkism.
A cave troll (MM3) has a humanoid form and would normally be allowed to combine it's natural attacks with weapon attacks. (For example, by wielding a greatclub and using its bite as a secondary natural attack.) Since monks can strike with any part of their body as part of a flurry, they don't even have to "waste" a claw attack to hold a weapon. As a result you get a "regular" flurry (with +9 Str bonus) on top of all the cave troll's natural attacks (as secondary attacks).