In the first days of the world arose a civilization of men. This civilization was based around the idea of becoming perfection. they worshiped the dread snake god Uhilar(changing). They saw the shedding of old skins as the way to immortality. The experiments began with the noblest of intentions, to make their people strong and ageless. Soon it became something dark and twisted. Now they call themselves the Ulan-Ati(snake men), called Yuan-Ti by those not of the blood.
They live in the deep jungle and harshest deserts. They seek to remain hidden and unobserved, only venturing out when there is magical knowledge or a species they wish to study. Ulan-Ati society is divided into three clades. Each is so specialized or metamorphosed as to appear to be a separate race all together. There is a hierarchy amongst the clades but it is not a rigid caste system. Mostly it is a recognition of purpose and breeding. Ulan-Ati have been breeding the clades to be specialized since the dawning of the world.
The most commonly known clade is the Naj(pure). They are the rulers and diplomats of their society. They are often encountered when they begin to gather up the disaffected youths of a region. They form cults to Uhilar, seeking slaves and breeding stock for their race. They appear as the First Men appeared, tall, strong, and attractive. the only physical difference is the slitted eyes and forked tongue.
The Sepgaruh(half blood) clade deals with focused study. Whether it be the strange serpentine martial arts or the mass breeding programs, the Sepgaruh are there to make sure the plans of the Ulan-Ati come to fruition. They serve as soldiers, engineers, slave masters, brood lords. They have the appearance of half-man half-snake. They have no legs, only the lower half of a great serpent.
The least understood clade is the Yangeji(abomination). They are the high priests of Uhilar. Beings so dedicated to his will that they sacrifice their very form to him. Each has unique mutations, blessings, and curses placed upon there bodies and minds. Each is a unique work of genetic art. Other races find them completely monstrous and alien in both form and mind. The Ulan-Ati find them compelling and beautiful.
the Ulan-Ati have collected slaves throughout the centuries. They are the masters of the world and see menial labor as beneath them. They instigated many breeding programs on these slaves over the centuries, but for some reason they did not take. The priests claim that specialized breeding was destined only for the Ulan-Ati and that is why it fails with the slaves. They still try, though, making the slaves more monstrous with every generation.
Aspects: I seek Apotheosis, Uhilar leads us to Immortality, Terrifying appearance, Alien mind
These are always created as master villains and always as clerics. Describe them as horrifying and terrible as you like. These are kind of my version of high priests of some Lovecraftian Great Old One.
Special: they are all unique and so each has a special ability that separates it from the rest of the Abominations. Here are three sample Mutations. Thick Scales: you gain a number of extra minor consequences equal to the number of beings you are facing. Venomous Bite: When you make a bite attack on someone in the same zone as you and succeed with style, they will continue to take one stress a turn until someone in the same zone as the poisoned person makes an intelligence check versus your wisdom modifier. Constrictor: When you use strength to create the grappled aspect on a character they must either attack you every round or try and free themselves(a vs strength roll) every round. they cannot attack anyone else until they are free. If you move a zone with someone grappled they move with you.
Aspects: I am the Heart of the Empire, The plan WILL work!
Good(+2) at: Pick a specialty that they are best at, fighting, planning, leading through fear
Bad(-2) at: Lying, compassion, inspiring people
Stress:  
Special: Half-bloods study and plan. Every now and again this means they can use some bit of esoteric knowledge and be able to do something they never could otherwise. Once per scene the Half-blood can roll something it is bad at as though it were good at it.
Aspects: Sepentine Charisma, Come into my parlor, You will become as a god if you follow me
Good(+2) at: Lying, Making speeches, being convincing, tactics
Bad(-2) at: Perceiving a lie, genuine emotion, facing the truth
Stress:  
Special: gain a +2 to sense emotion from smell using their tongues(like a snake testing the air) or through sight cues(enhanced vision).
So there is my take on Yuan-Ti. I gotta say I kind of hate these guys, from a fiction standpoint. they are sort of crazed slave owning Nazis worshiping a Great Old One. The more I wrote about them, the more I really despised them. Let me know what you think of them, as I really am not sure if I should include them. I mean they are bad guys, yeah, but they are just so damned irredeemable and nasty. I don't know. what do you all think? Any comments, concerns, or suggestions would be welcome. The next post will be on the Dark Elves. So that should be fun. I have already written a little bit about them, but now they finally get their own complete write up. Should be interesting.