Hybrid creatures were extremely popular in Medieval Times, usually found on the margins of the written text. In Medieval culture and iconography, hybrids held an aesthetic and a didactic purpose: the Medieval person would have believed that sin, monstrosity and damnation, represented by the monstrous hybrid creature, lurked to the margins of the manuscript, while salvation and grace would have been found inside the written text.
To learn more about Medieval manuscripts, please visit our relevant blog post: A Brief History of Manuscripts.