Any way, as you can see form the name, I took the yuan-ti name and switched it around and added the di- I was looking for a usage of two or doe and came up with this. The name is pronounced TEE die-yawn.
It is also influenced by the marilith, with a twist.
Anyway...as always I would like your input and feedback (sorry Nyt, but I was itching to post this and did not send it to you to look over first).
I think there may be an error on the attacks- I am thing (?) the attack bonuses are correct but I am sure that the damage from their strength is wrong - especially for their tentacles and second pair of arms. In my defense I did 99% of this at work with only the SRD to reference (it has really slowed down for me here).
Enjoy and let me know what you think.
Ti-diyaun
Large monstrous humanoid (psionic)
Hit Dice: 13d8+78 (136 hp)
Initiative: +4
Speed: 40 ft.(8 squares)
AC: 25 (-1 size, +4 Dex, +12 natural), touch 13, flat-footed 25
Base Attack/Grapple: +13/ +28
Attacks: Large bone greatsword +19 melee (3d6+9) or large alhulak +19 (1d8+7) or tentacle +19 melee (1d10+7) or stinger +19 melee (1d6+7 and poison)
Full Attack: Large bone greatsword +19/+14/+9 melee (3d6+9) and 2 alhulaks +19 melee (1d8+5) and 2 tentacles +17 melee (1d10+3) and stinger +17 melee (1d6+3 and poison)
Space/Reach: 15 ft/10 ft (15 ft with tentacles)
Special Attacks: Constrict 1d10+9, improved grab, poison, psi-like abilities
Special Qualities: DR 10/ bludgeoning or metal, improved uncanny dodge, mental duality, naturally psionic, paired mind, uncanny dodge
Saves: Fort +10, Ref +12, Will +14
Abilities: Str 24, Dex 19, Con 22, Int 17, Wis 15, Cha 20
Skills: Bluff +10, Concentration +13, Diplomacy +12, Hide +7, Intimidate +15, Knowledge (psionics) +8, Listen +10, Move Silently +11, Psicraft +10, Search +11, Sense Motive +12, Spot +12, Survival +8, Use Psionic Device +13 (+15 to use power stones)
Feats: Combat Expertise, Combat Reflexes, Multiattack, Multiweapon Fighting, Weapon Focus (greatsword)
Environment: Sandy Wastes or Stony Barrens
Organization: Usually solitary
Challenge Rating: 14
Treasure: Standard coin, double gems and psionic items
Alignment: Chaotic/Evil
Advancement: 16-19 HD (Huge) or by character class
Level Adjustment: +4
Two heads rest upon the broad shoulders of the creature before you, one with the high cheek bones, rounded chin, and full lips of a woman; the other with the heavy brow and solid looking jaw of a man. Attached to the deeply tanned human-like torso are two pairs of very strong arms and two long, scaled tentacles that end with jagged bone spiked pads. Below the waist, the creature has the serpentine body of a snake, colored like dark sand and banded with black diamond shapes. The end of the tail ends in a heavy stinger similar to that of a giant scorpion. An evil gleam and cruel smile graces the lips of both heads as their blood red snake-like eyes look for something to kill.
It is unknown where there creatures originally came from, though it is rumored that they hail from a land across the vast Sea of Silt. Where ever their original home, tales of these creatures attacking travelers, caravans, and small villages have been increasing over the last several years.
Both heads of this creature have red serpent like eyes and split tongues, which they use to augment their other senses. They almost always have long black hair, with the female head usually styling it in some manner they have seen on other women. The four arms and tentacles are attached at the sides of the long torso of their human-like upper half and the skin of the heads, torso, and arms is deeply tanned. The tentacles are scaled in the same color and pattern as the rest of their snake-like body. Below the waist, the ti-diyuan has the body of a huge snake and are about twenty feet in length.
These beings have a deeply twisted sense of fun, gaining pleasure from the torture and killing of any creature that crosses their path. Both heads usually get along quit well and chat on like a married couple, but their evil and hateful nature of living things usually causes then to hunt down and kill anything that crosses their path. There are a few exceptions to this sometimes. In some rare cases, they will take some creatures captive and use as slaves. The especially love music and psionics and will will sometimes allow bards and anyone possessing a strong psionic ability a chance to live as long as they either play music for them or teach them some psionic lore. The ti-diyuan are fickle creatures and bore quickly. Once their amusement grows stale they will slay their slaves or entertainers on a whim and move on.
The ti-diyuan can speak it's own language, common, giant, gith, and elven. All ti-diyuan refer to themselves as “we” no matter which head is speaking, though each head will have it’s own name. Also, because of their forked tongues, the ti-diyuan speak with a serpentine lisp. Due to their natural mind link psi-like ability, the ti-diyuan has the ability to speak mentally with any sentient creature.
Combat-
In battle, the ti-diyuan is a truly terrible foe, able to lash out in all directions and skip around he battle field at will to reap carnage. For weapons, they prefer edged and slashing weapons and usually carry an assortment of these weapons on them and will have a large store of them in their lair.
As an intelligent and cunning creature, they use their psionic abilities to move around the battlefield using dimension slide to take out spellcasters and psions, using their poison to immobilize them to learn fro later as long as the had not inflicted serious harm to the ti-diyuan. Against physically powerful warriors, the ti-diyuan will use their psionic ability of forced shared pain, death urge, and psychic crush to take them out faster. They have also been known to manifest their energy wall to slow down foes in order to use their psionic dimension door to leave if badly wounded, though they will return when physically able to get the creature out of their land. If there is time, the ti-diyuan will always manifest their force screen before engaging opponents.
Constrict (Ex): A ti-diyuan deals 1d10+10 points of damage with a successful grapple check. The save DC is Strength-based.
Improved Grab (Ex): To use this ability, a ti-diyuan must hit with its tentacle attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it succeeds on the grapple check, it can constrict.
Poison (Ex): The ti-diyuan’s poison is one of it’s favorite tools to prolong the “playtime” it has with a creature. When hit with the stinger of this creature’s tail, the victim must make a Fortitude save DC 22. Failure inflicts 1d6 temporary Dexterity damage to the creature and paralyzes them for 1 minute. Secondary damage is paralysis for 1d6 additional minutes. Once a creature succumbs to its poison, the ti-diyuan will ignore them if there are multiple targets attacking it, wanting to keep the paralyzed creature alive so it can interrogate and or torture it as the whim takes the ti-diyuan.
Psi-like abilities: at will- detect hostile intent, detect psionics, demoralize (DC 21, 60’ radius), dimension slide (manifest as move action, range 55’) , mind link, psionic charm person (DC 20- effects aberrations, animals, dragons, elementals, fey, giants, magical beasts, monstrous humanoids, or outsiders); 3/day- correspond, energy wall, force screen (+7 shield bonus to AC), forced shared pain (DC 22), mind thrust (DC 22, 13d10 damage) , psionic dimension door (manifest as move action), thought shield (PR 23, duration 11 rounds); 1/day death urge (DC 20, duration 2 rounds), psychic crush (DC 20, target gets +4 to Will save, failure drops target to -1, success deals 5d6 points of damage) . Manifester level 13th. All powers are augmented for manifester level. The save DCs are Charisma-based.
Improved Uncanny Dodge (Ex): The hyper vigiliant senses and two heads allows the ti-diyuan denies it’s opponents the +2 bonus to strike if they are flanking the creature and also ability to sneak attack the ti-diyuan by flanking it, unless the attacker has at least four more rogue levels than the ti-diyuan has Hit Dice.
Mental Duality (Ex): Due to the two heads of the ti-diyuan, this creature is highly resistant to mental assault. They have a +4 racial bonus to all Will saves and if one or both heads are targeted with a mind affecting power or effect, then both heads are allowed a Will save. If either head succeeds in the save, then the mental attack fail to overcome their shared consciousness.
Naturally Psionic: A ti-diyuan gains 3 bonus power point.
Paired Mind (Sp): The ti-diyuan’s two heads share a deep and constant mental bond, allowing them to share thoughts instantly. This shared consciousness also grants them several other benefits. Similar to the psionic power schism, the ti-diyuan may take an additional standard action each round as long as it is purely mental or verbal. This allows the creature to manifest an additional power, activate an item with a verbal command, or to even cast a spell that only has verbal components (if they have a class that allows them to cast spells).
Uncanny Dodge (Ex): Because of their twin heads and serpent-like senses, the ti-diyuan is almost never caught unaware and can react to danger before her senses would normally allow her to do so. As such the ti-diyuan retains it’s Dexterity bonus to AC even if it is caught flat-footed or struck by an invisible attacker. However, the ti-diyuan still loses it’s Dexterity bonus to AC if immobilized.
Skills: Ti-diyuan receive a +4 racial bonus to Listen, Search, Sense Motive, and Spot checks.
Feats: In combination with its natural abilities, a ti-diyuan’s Multiweapon Fighting feat allows it to attack with all its arms at no penalty.
Society-
The ti-diyuan as a race are hermaphroditic, being able to lay their eggs and fertilize them without the need for a mate. Since they have no need to gather together to mate, meeting more then one of these dreadful creatures at a time is a truly rare event. Ti-diyuan will carry their unborn young within their bodies for about a year after which they will lay around five to six of the leathery eggs in an area of very hot sand within their territory and leave them to continue to incubate. Upon hatching, the young will fight among themselves until all but one is dead or driven off. The victor will then consume their first meal- the bodies of its siblings. The ones driven off almost always die. If parent and child meet again, the parent will more then likely kill their young.
Land and territory controlled by a ti-diyuan is almost completely devoid of sentient life, as they will usually try to kill or enslave any other sentient creature they meet, even those of their own race, to prevent the others from taking the area they have staked out as their own territory.
As stated above, the ti-diyuan will sometimes take other creatures as slaves. Those taken as slaves or entertainment will almost always be subject to a barrage of psionic charm person until the ti-diyuan can confirm that they have succumb to the effect by using their detect psionics ability.
Hit Dice: 13d8+78 (136 hp) Very minor nitpicking about how average hp are calculated.
Base Attack/Grapple: +13/ +24 13 BAB + 7 Str + 4 Size = 24
Attacks: Bone greatsword +19 melee (3d6+8) or alhulak +19 (1d8+7) or tentacle +19 melee (1d10+7) or stinger +19 melee (1d6+7 and poison) Remember these are large weapons. The greatsword gets -1 damage because it is made of bone.
Space/Reach: 10 ft/10 ft (15 ft with tentacles) Should be 10 ft.
Special Qualities: DR 10/bludgeoning or metal Should this really be "or"? A monster of this CR should perhaps have a "and" instead.
I did not check the skills, these are actually easier do redo than they are to check if someone else made them. Believe me, I did check a lot of stat blocks.
/rule master mode off
/rule master mode on
Hit Dice: 13d8+78 (136 hp) Very minor nitpicking about how average hp are calculated.
Base Attack/Grapple: +13/ +24 13 BAB + 7 Str + 4 Size = 24
Attacks: Bone greatsword +19 melee (3d6+8) or alhulak +19 (1d8+7) or tentacle +19 melee (1d10+7) or stinger +19 melee (1d6+7 and poison) Remember these are large weapons. The greatsword gets -1 damage because it is made of bone.
Space/Reach: 10 ft/10 ft (15 ft with tentacles) Should be 10 ft.
Special Qualities: DR 10/bludgeoning or metal Should this really be "or"? A monster of this CR should perhaps have a "and" instead.
I did not check the skills, these are actually easier do redo than they are to check if someone else made them. Believe me, I did check a lot of stat blocks.
/rule master mode off
Thanks Terminus Vortexa and Elonarc-
As for your comments Elonarc-
1. The hp I rounded up- no reason why but I did- it is fixed.
2. The grapple I calced as if they had Improved Grapple, because originally I had that as a bonus feat for them- I thought that Improved Grab would work simulary so I did not change it. Does anyone know if it does ot does not? If not then I will give the Improved Grapple as a bonus racial feat.
3. As for the weapon- they are only large if I say they are...which I was going to do but forgot to change. The -1 to damage for the bone was calculated in there though (+7 for Str +3.5 for two handed = 10.5 rounded down to +10 -1 for inferier materials = +9 damage :D So I win that one :P
4. As for the Space/Reach- I was pretty sure that you could have a creature that took up a 15' space if they were long. This critter is about 20' long from heads to tip of tail. If some one knows for certian then let me know but I think that you can have it 15' if they are long. Someone might know the answer to this one.
5. I am torn with the DR- one one hand the reason I have it 10/ bludgeoning or metal is because of how I see the serpent body structure (I did the same thing of the morterren asp). I see most bladed weapons sliding off of the thick scales, kind of like a kights armor in the middle ages. Metal could bite deeper into the creatures scales and bludgeoning would...well crush them. How about making the DR 15/ bludgeoning or metal instead of 10/ bludgeoning and metal?
As for the skills- the only one I am unsure of are Hide and Move Silently - I think that large creatures get a size penality for those two skills.
I also need to add languages that the creature speaks too.
Nice work Kal. Any idea how say a city-state made of Ti-diyaun and other lizard folk say on the other side of the sea of silt might work? It might be a cool stop, if not lethal stop, for a group of pc's I have! 
Now there could be ruins of a city-state like society across the Sea of Silt that these creatures once ruled by, like all good things, it came to an end...most likely a violent and bloody end.
I have not really delved too much into the idea of taking the ti-diyuan to a larger level - it would really depend on how, or IF, the yuan-ti have a place within Athas.
It would be interesting and i might be persuaded into coming up with more critters and/or additional material for the ti-diyuan if there was enough interest.
Thanks rjtrotter for the praise and I hope your PC's hate me for what you are about to unleash on them- I know mine will :D
I do have an idea for a high level one of these, a ti-diyuan with seven levels as an egoist with the metamorphosis power- it could be very interesting to see how a group of players would deal with a situation if they were manipulated into leading a large caravan in to this creatures territory by a woman who is actually the ti-diyuan, and when the players learn that the people they thought were being led to safty come up all dead, then the players would be hell bent on finding out who did it- onlt to discover later that they had been played by this powerful creature and that they (the PCs) were the ones kind of responsible for leading all of those people to their deaths.
I am an evil S.O.B. :evillaugh
1. large creatures get a -4 to hide checks but no penalty to move silent.
2. how much of a presence do yuanti have in DS? I remeber that they were listed as an appropriate monster in the old box sets but i have never seen any reference to them beyond that.
3. do you have access to the FR product Serpent Kingdoms? I found myself flipping back and forth to that book while reading the House of Serpents series. It has a lot of feats, items, and spells (with a little work, one could convert them to psionic powers pretty easily) that could be transfered to DS.
4. I'd like to hear anymore lore on the ti-dayuan.
Thanks for the research on the hide thing- I will fix that.
As for the serpents book- let me check....nope. I thought I had it in PDF.
As for yuan-ti presence in DS- of that I am unsure. It has been debated but nothing solid has ever been said- I could be wrong though.
As for more lore on the ti-diyuan...I will see what I can do.
Ideas?
just an idea.
That is all you are getting for now :D I will let my creative juices to continue to flow with this idea and I will hopefully have a write up of additional history, location of origin, and the "how" they came to be- it will be Legendary!
I will also be adding a not in the advancement that when making the creature Huge it gains +4 Str, +4 Dex, and +4 Con instead of the usual +8 Str and +4 Con- these creatures get kind of leaner and swifter instead of bulkier.
And there will be more to come with origin information.
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The Cultists of Yeshlem
Nestled in the broken folds of a black land, beneath almost perpetually gray skies and the towering triple peaks of long-smoldering volcanoes, lies the terrible city of Yeshlem. Here, the serpent-god rules, and his coils wrap tightly around the people of the land.
The greener lands around the city, far from the smoking calderas, are populated by numerous destitute villages, who fear the snakes that rule the land, for the serpents demand tribute and raid mercilessly for human cattle, slaves and breeding stock.
Raids are led by the Cultists of Yeshlem: human madmen enslaved to the will and pleasure of the serpent-god, cattle uplifted and glorified in their service and given strange powers to strike down those who defy the serpents' will.
This is the world, for beyond these lands lie nothing more than the endless, deadly plains of gray ash where unquiet spirits dwell and the frozen fields of poisonous ice, from which flows the unclean river of Sseshtos...except for the legend of a better life in the fabled paradise known as the Valley of Tears, where no serpent dwells and men live under the protection of benevolent gods.
The City of Glorious Scales
The city of Yeshlem-above lies mostly in ruins, populated by half-breeds and human slaves who are bred into the squalor of its broken streets, while the serpent-blessed have burrowed tunnels and chambers deep into the heated ground of Yeshlem-below. This is their city, carven from the volcanic stone skillfully, if hellishly and inhumanly.
These are not crude tunnels burrowed in the earth, but works of art and architectural design worthy any intelligent, civilized race. Featuring rounded tunnels and circular chambers with numerous quiet nooks, gently curving and spiraling layouts, the whole is the domain of the serpent-blessed, and only tread occasionally by the human feet of cultists come to see their god.
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As you can see, I did not get very far in this write-up, and it needs some editing, but there are some bits to build on in there, and some implied conflicts as well.