Does one have to be a humanoid in order to be a Monk?

[Arkat]

What if one of the Imperial dragons (a Young Adult Underworld Dragon let's say), wanted to take class levels in Monk? Could they do it? If so, would their Monk hit dice stack with their Underworld Dragon racial hit dice?

Also, what would they use for weapons? Their Unarmed Strikes (for Flurry attacks) or their Claws, Bite, Gore, and such?

I assume they get Ki and can have full access to whatever Ki powers they would like to take.

[Mysterious Stranger]

There is no reason they could not take levels in monk. The HD would stack, they could use either their natural attacks or the unarmed attacks including flurry. Feral Combat Training would allow you to use one of your natural attacks with your flurry of blows, but does require weapon focus for the natural attack. But keep in mind that the dragon’s natural attacks are actually better.

You would gain everything a monk of its level gains.

[Pizza Lord]

Just adding on to Mysterious Stranger's answer. There is no reason a creature can't take levels of monk in most cases (restrictions, like alignment not withstanding). The monk HD will stack with the racial.

For a general rule (meaning I am not going into archetypes or feats or abilities), a monk cannot use their natural attacks to flurry or to deal monk unarmed strikes. The dragon would have an unarmed strike (as most creature's do). A monk's unarmed strikes, meaning the ones that deal different damage than a normal creature's, which are usually based on size, must come from fists, elbows, knees, or feet. So as long as the creature has at least one of those, the dragon could make monk unarmed strikes and flurry.

I think most GMs will agree that dragons at least have feet, so unless they are bound or otherwise out of play, the dragon monk can use them for a flurry or monk unarmed strike.

Monk > Flurry of Blows wrote:

A monk cannot use any weapon other than an unarmed strike or a special monk weapon as part of a flurry of blows. A monk with natural weapons cannot use such weapons as part of a flurry of blows, nor can he make natural attacks in addition to his flurry of blows attacks.

Monk > Unarmed Strike wrote:

A monk’s attacks may be with fist, elbows, knees, and feet.

[Diego Rossi]

Dong that would normally fall under the rules on p. 296 of Bestiary 1: Adding Class Levels.
Those rules don't speak of archetypes as they didn't exist when Bestiary 1 was printed, but I see no reason why they couldn't be used.

Determining the effect on the dragon CR is tricky. It is even more difficult if he is meant to be a player companion or a PC.

[Arkat]

Diego Rossi wrote:

Determining the effect on the dragon CR is tricky. It is even more difficult if he is meant to be a player companion or a PC.

Indeed.

That's why I'm thinking of awarding the PC Monk with the ability to use a "Form of the Dragon"-type ability (similar to the Imperial Dragon's Change Shape ability 3x per day) instead of turning them into a true dragon.

Won't be nearly as powerful, but they'll still be able to turn into a dragon for an extended period when needed.

Thanks all!

[Arkat]

Pizza Lord wrote:

I think most GMs will agree that dragons at least have feet, so unless they are bound or otherwise out of play, the dragon monk can use them for a flurry or monk unarmed strike.

I think you could also argue that a balled up claw could count as a "fist," too.

Thanks!

[Diego Rossi]

Arkat wrote:

Pizza Lord wrote:

I think most GMs will agree that dragons at least have feet, so unless they are bound or otherwise out of play, the dragon monk can use them for a flurry or monk unarmed strike.

I think you could also argue that a balled up claw could count as a "fist," too.

Thanks!

A Monk is less limited than other characters when using IUS:

CRB wrote:

A monk’s attacks may be with fist, elbows, knees, and feet.

The only problem is he wants to use the Form of the dragon's natural attacks instead of the unarmed damage for his class level and new size. The size change will probably give him a nice damage increase.

[Arkat]

Diego Rossi wrote:

Arkat wrote:

Pizza Lord wrote:

I think most GMs will agree that dragons at least have feet, so unless they are bound or otherwise out of play, the dragon monk can use them for a flurry or monk unarmed strike.

I think you could also argue that a balled up claw could count as a "fist," too.

Thanks!

A Monk is less limited than other characters when using IUS:

CRB wrote:

A monk’s attacks may be with fist, elbows, knees, and feet.

The only problem is he wants to use the Form of the dragon's natural attacks instead of the unarmed damage for his class level and new size. The size change will probably give him a nice damage increase.

Agreed. The player in question is playing a Kobold Monk, so 2d8 damage with Unarmed Strike at 20th level.

If he can Change Shape into a Huge dragon, that should be 6d8 for a 20th level Monk according to my calculations. Very nice.

[Azothath]

Rules wise classes are desinged with humanoid PCs in mind. There are some PCs that are a bit odd.
I know some people say if it is not defined it's allowed, but often RAW wise it is only permitted if addressed otherwise you are in GM territory.

The rest is homebrew or done under the aegis of GM with monsters to create challenges.