This paper examines the demons Pazuzu and Lamaštu from a cognitive science perspective. As hybrid creatures, the iconography of these demons combines an array of anthropomorphic and zoomorphic properties, and is therefore marked by a high degree of conceptual complexity. In a technical sense, they are what cognitive researchers refer to as radically “counterintuitive” representations. However, highly complex religious concepts are difficult in terms of cognitive processing, memory, and transmission, and, as a result, are prone to being spontaneously simplified in structure. Accordingly, there is reason to expect that the material images of Pazuzu and Lamaštu differed from the corresponding mental images of these demons. Specifically, it is argued here that in ancient cognition and memory, the demons would have been represented in a more cognitively optimal manner. This hypothesis is further supported by a detailed consideration of the full repertoire of iconographic and textual sources.