Let's see..... I'd make it something like this perhaps.....
Quan-Ri (random name from mutilating the word quad, probably too close to yuan-ti)
Small Outsider (humanoids are supposed to conform closely to the general human shape, and while a tail is acceptable, an extra two arms might be a bit too different)
As Small creatures, Quan-Ri gain a +1 size bonus to Armor Class and on attack rolls. They also gain a +4 size bonus on Hide checks. They require less food and drink than Medium creatures would,a nd they use mostly lighter-weight gear. However, they also have less carrying capacity and so does their gear. As Small creatures, they deal only 1d2 subdual damage with unarmed strikes, and they must use smaller weapons than Medium creatures do. They suffer a size penalty on certain checks as well, in cases where greater height and mass would have been advantageous, such as when grappling.
As outsiders, Quan-Ri are not subject to effects that only function on humanoids, such as Enlarge Person or Charm Person, but instead they are vulnerable to effects that function against outsiders, such as the hedging effect of Protection from Alignment spells. However, Quan-Ri are considered native to the Material Plane, so they need to eat, drink, sleep, and breathe just like humanoids do, and they age like humanoids as well.
-2 Strength, -2 Charisma: Quan-Ri are small and have less muscle mass than most humanoids, and their extraplanar origins give them an odd mindset, even though they have long since become attuned to the Material Plane since their exodus there. Quan-Ri are also wary of other intelligent creatures and their general distrust of others makes it more difficult to deal with other races. Their torsos are somewhat bulky; and on such a squat frame, their four arms tend to get in eachother's way as often as not. Thus they lack some of the grace and dexterity of other small folk.
Speed: Quan-Ri base speed is 20 feet.
Four-Armed: The Quan-Ri are mostly humanlike in form, but have four arms, two on the left side of their torso and two on the right. Quan-Ri have access to, but do not automatically gain, the Multidexterity and Multi-Weapon Fighting feats. Any effect that would grant a Quan-Ri Ambidexterity instead grants them Multidexterity, and any effect that would grant a Quan-Ri Two-Weapon Fighting instead grants them Multi-Weapon Fighting. Any effect that would grant them Improved Two-Weapon Fighting instead grants Improved Multi-Weapon Fighting. However, like humans, most Quan-Ri are only particularly skilled with one hand, with the few others being those who take the aforementioned feats as some of their normal character level feats.
A Quan-Ri is able to use each arm as effectively as a human would, except for the Quan-Ri's lesser Strength and size. As noted above, Quan-Ri normally have one primary hand and three off-hands. Each arm can be used for unarmed strikes or wielding weapons or using shields or other activities. However, like a human, the Quan-Ri cannot effectively use more than one shield at a time for defense. Quan-Ri gain a +1 racial bonus on Climb checks when they use three hands to climb, or a +2 racial bonus when using all four hands to climb. Likewise, if using an extra hand for grappling, they gain a +1 racial bonus on grapple checks, or a +2 racial bonus if using both extra hands for grappling.
Darkvision 30 feet: Quan-Ri have a limited capacity to see without light, out to a distance of 30 feet. Darkvision is black and white only.
Endurance: Quan-Ri gain this as a racial bonus feat. Former slaves from the Elemental Plane of Earth long ago, their people are used to toil and hardship, which left its mark on them even if they now live relatively free.
Stonecunning: From their long heritage in the Elemental Plane of Earth, the Quan-Ri have keen instincts for finding their way safely and consistently through vast tunnel warrens. They have the Stonecunning trait exactly like that of Dwarves.
+2 racial bonus on Balance, Climb, Craft, and Profession (Miner) skill checks: The Quan-Ri retain many talents and instincts from their generations of servitude as little more than slave-labor chattel to Dao, the earth-elemental relatives of Djinn and Efreet.
Spell-Like Ability: Once per day, a Quan-Ri can use either Soften Earth and Stone or Endure Elements as a spell-like ability. This functions as per either druid spell of the same name, but has no components. Their effective druid level for this purpose is equal to their character level. Any save DCs are Charisma-based, as normal for spell-like abilities.
Automatic Languages: Common and Terran.
Bonus Languages: Any, except secret languages like Druidic.
Favored Class: Highest-level class at any given time.