In several European languages lexical items meaning “cat” also designate the “monkey”, the “drunkard” (or “drunkenness”), several “insects” and some supernatural creatures. Those coincidences – here termed “semantic parallelisms” – are in fact intimately associated and constitute a network of beliefs linked with the medieval carnival. Building up on the pioneer work of Sainean (1905) and previous works by the author (Masson 1999), this paper illustrates the importance of semantic parallelisms not only from the linguistic viewpoint but also from the anthropological and cultural viewpoints. It shows that the semantic parallelisms stem from the cross-culturally recurrent conception of these living beings as connected to supernatural powers, giving rise to semantic shifts such as “scarecrow”, “frighten”, “devil” or “have the gift of witchcraft”.