Medieval authors placed fantastic creatures in the borders of manuscripts, since they mark the boundaries of our understanding. 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. According to apocalyptic visions of the Bible, they will also proliferate as we approach the end of time. Because they challenge our conceptual powers, fantastic creatures also seem to exist at the limits of language. Legends tell us that imaginary animals belong to a primordial time, before we had encompassed the world in names, categories and elaborate conceptual frameworks. This richly illustrated book shows how, despite their liminal role, grif?ns, dog-men, mermaids, dragons, unicorns, yetis and many other imaginary creatures are socially constructed through the same complex play of sensuality and imagination as 'real' ones. It traces the history of imaginary animals from Palaeolithic art to the Harry Potter stories and robotic pets. These ?gures help us psychologically by giving form to our amorphous 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.