Slander against the Islamic prophet Muhammad was rife in the Medieval Christian world. The religion of Islam spread rapidly and successfully, and in the agrarian hinterlands of Western Europe, many people’s fear of Islam was matched by their ignorance of it. Many depictions of Muhammad from the 12th to the 18th centuries reflect this.
Here, you see the first extant Western European image of Muhammad, from the 12th century manuscript _Corpus Cluniacense_, an important Latin work of several Arabic texts. With the Western Crusades and corresponding interaction of populations, Arabic became increasingly accessible. But an interest in these works didn’t mean Western Christians were sympathetic to Islam or its founder. So here, Muhammad appears as an ugly bearded face with a fish’s body.
Mixing human forms with other animals has a long history of showing that something is monstrous in Medieval culture. This appears in several defamatory and fictitious biographies of Muhammad written by Western Christians that describe his death. Often in these accounts, Muhammad’s corpse is dismembered and eaten, frequently by pigs.
For instance, the Latin Guibert de Nogent, in his writings about the First Crusade, claimed that Muhammad had died in an epileptic fit, and was afterwards devoured by pigs. By this time in Medieval Europe, pigs had taken on a symbolic meaning of disgust and filth. Christians — who kept pigs and ate them — frequently associated pigs with Muslims and Jews, two groups that they considered undesirable. (Irony alert, because of course neither of these populations ate pork.)
Sources: Image: Paris, Bibliotheque de l’Arsenal, lat. 1162, fol. 11r. _Sons of Ishmael: Muslims through European Eyes in the Middle Ages_, John Tolan, Univ Press of Florida, 2008, chapter two “A mangled corpse: the polemical dismemberment of Muhammad,” esp p 21