Banded Mongoose
Just read a book about the crusades and found a horde of Qara-Khitai mentioned: driven from their home China they were the predecessors of Jenghis Khan and his Mongols in attacking Persia.

I found it interesting to see the source of another part of REH's patchwork history.
Howard mentions the Khitai dynasty/kingdom in "Red Blades of Black Cathay" (which will be included in Lord of Samarcand and Other Adventure Tales of the Old Orient -- here's a flyer about the new Bison Books series). Chinese elements in a lot of his historical and contemporary stories allow us to guess how he imagined Khitai in the Hyborian Age.