Tales throughout the world generally place fabulous beasts in marginal locations - deserts, deep woods, remote islands, glaciers, ocean depths, mountain peaks, caves, swamps, heavenly bodies and alternate universes. Legends tell us that imaginary animals belong to a primordial time, before we had encompassed the world with names, categories and scientific knowledge. This book traces the history of imaginary animals from Palaeolithic art to the Harry Potter stories, and beyond. It shows how imagined creatures help us psychologically, giving form to our subconscious fears as 'monsters', as well as embodying our hopes as 'wonders'. Nevertheless, their greatest service may be to continually challenge our imaginations, directing us beyond the limitations of our conventional beliefs and expectations.