I never was a big fan of D&D 3.x. But there were some gems (well hidden) in and amongst its sourcebooks. Here's one, kitted out for use with BECMI:
In the high plateaus of Bhauta live the Yak Folk, a race of nomadic slave-owners whose utter indifference to other forms of life is easily mistaken for malice. They move around their mountain realm in clan groups numbering in the several dozen, herding both their yaks (who they view as their children) and their humans (who are seen as equal in status to all non-yak animals). Twice a year - once in spring when the snows begin to thaw, and again in autumn before the heavy snowfalls - they perform elaborate rituals before setting off to raid the valleys and foothills for more slaves. Life as one of their chattels is brutally tough, but the Yak Folk are generally sensible enough not to allow their slaves to die unnecessarily.
Yak Folk adults stand considerably larger than a man (6-7' for a female, up to 8' for a male), and they are covered in shaggy black fur. They are extremely vain, and enjoy elaborate, decorous clothing, especially dyed in yellows, reds and purples, and they usually adorn their horns with expensive silk tassels and scarves. The materials for clothing are often stolen on slave raids, where the Yak Folk take great care to select only the very best and most expensive looking goods.
Yak Folk are equally powerful in magic and combat. In a fight they wield short, heavy scimitars and kukri knives, and can also gore with their horns (although they view this vulgarity as a last resort). They prefer illusory spells which confuse and befuddle their opposition, and often employ such tactics to subdue an enemy; opponents are usually worth more alive as slaves than they are dead.
Armour Class: 3
Hit Dice: 5
Move: 120' (40')
Attacks: 2 scimitar/1 horns or 2 kukri/1 horns
Damage: d8+4/d8+4/2d6 or d4+4/d4+4/2d6
No. App: 3d4 (raid), 6d6 (clan group)
Save As: Cleric 8
Treasure Type: E
Each Yak Folk encountered also functions as a magic user (Wokan) of level 4, except for one of their number, who will be a level 6 Wokan.
Once per day, three Yak Folk can perform a ritual to call 2d4 Lesser Djinni to their aid. The ritual takes two rounds, during which the Yak Folk cannot be disturbed. Any summoned Djinni serve for the length of the combat before returning to the elemental plane of air.