A psychological basis for belief in human monsters is provided by the possibility of human aberrations, instinctive human fear and fascination for such prodigies, and the existence of barbaric tales ridiculing foreigners. The role of language as a cause for such belief is investigated, specifically in terms of folk etymologies for more or less corrupt ethnonyms. The most common explanation to account for reports of monstrous races states that such stories are of literary origin, and are based, for example, on ancient Indian epics recorded by Greek writers. The Greek names for monstrous races are simply literal translations of descriptive Indian designations. The explanation offered here involves the human tendency to incorporate foreign terms into the purposely limited but efficient stock of sememes of a given language through associative etymology. The implications of this process for the relationship between language and concept-formation are briefly mentioned and an inventory of monstrous races and their names is provided. (CLK)