The wholly abominable creatures, possibly related to the Mi-Go, obliquely referred to in "The Whisperer in Darkness" and "The Shadow Out of Time." They actually belong to August Derleth and Mark Schorer who created them in "The Lair of Star-Spawn." The tale explained that these people living high in Burma where, according to Chinese legends, living in the lost city of Alaozar on the Isle of Stars in the Lake of Dread on top of the Plateau of Sung. In the (PR), Wax artist George Rogers created a bizarre "oblong swimmer in darkness" based on images from there. (???) They may have been spawned by an attraction by fantasists of the time to Robert W. Chambers' "The Slayer of Souls" in which the Tchortcha of Tibet are mentioned as the servant/soldiers of the Slayer of Souls.
("The Whisperer in Darkness" and "The Shadow Out of Time") ([P.Rev.] "The Horror in the Museum")