This volume examines various manifestations and understandings of the concept of monstrosity in medieval Europe around 500-1500 ce through a collection of contextual chapters and primary sources. The main chapters focus on a specific theme, a type of monster or representation of monstrosity, and consist of a contextual essay synthesizing recent scholarship on that theme, excerpts from primary sources and a bibliography of additional primary and secondary sources on the topics addressed in the chapter. In addition to building upon the wealth of scholarship on monsters and monstrosity produced in recent decades, the book engages with the current fascination with monsters in popular culture, especially in movies, television, and video games. The book presents a survey of medieval monstrosity for a non-specialist audience and provides a theoretical framework for interpreting the monstrous. This book is ideal for undergraduate students working on the theme of monstrosity, as well as being useful for undergraduate courses that cover the supernatural and manifestations of the monstrous covered in the book. With materials drawn from a wide range of medieval sources, it will also appeal to courses in English, French, Art History, and Medieval Studies.