The Black Ones are creatures who live on an island and have a pool which turns humans into figures. The Black Ones have an instrument, similar to a pan flute, that produces no sound. When some of the Black Ones play this flute, it causes the victim's muscles to contract with an effect that makes it look like one is dancing. At the end of this painful dance, the Black Ones grab their victim and proceed to toss them into the Black Pool. After the victim is removed from this mysterious body of water, they will be shrunken and ossified. (Source : Conan Wiki)

« These creatures were black and naked, made like men, but the least of them, standing upright, would have towered head and shoulders above the tall pirate. They were rangy rather than massive, but were finely formed, with no suggestion of deformity or abnormality, save as their great height was abnormal. But even at that distance Conan sensed the basic diabolism of their features. (...) Conan mentally termed the creatures black men, for lack of a better term ; instinctively he knew these tall ebony beings were not men, as he understood the term. »

Robert E. Howard - The Pool of the Black One

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