Dragons have been around for a very long time.  They are one of the very few mythological creatures that have become absolutely central to popular culture; everyone knows what a dragon is. There are other important and well-known mythological creatures, but none are as ubiquitous as dragons, which can be found in Europe and the Americas, in classical and Biblical traditions, in ancient Indian tales and across Asian mythology.  So where do dragons come from? Why are they so common across cultures, and what do they mean to us today?  I chat to Professor Scott Bruce, author of the recently published Penguin Book of Dragons and an authority on dragons from antiquity to the present day.