For as long as people could write and think up stories, Dragons have been in existence. Some people believe that they once flew the skies for real, others hold differing opinions, from those who believe them to be pure fiction, to others that believe that they are creations from the imagination with origins a little more mundane. There is no doubt that creatures once existed on earth that you could easily mistake for a dragon. The Megalania Prisca (otherwise known as the giant ripper lizard) was apparently able to reach a length of over seven metres. It ate medium to large sized animals.
Today, living large lizards, such as Monitor lizards would still give you a nasty shock (and much more) if you were caught alone with one in a dark alley.
For my mind, dragons at some stage did exist, but perhaps we have romanticised them somewhat and crafted them to fit our stories. After all, Dragons fly but not lizards. However, there are close cousins to the species that ‘jump’ large distances, gliding between trees. Birds are the mammalian version and distant relatives to lizards, so further down the evolutionary tree, lizards do really fly once they evolve from a cold blooded to a warm blooded species. It is an interesting debate and the very existence of such magnificent beasts existing for real is quite thrilling. That is why I believe that they fascinate us so much. They are also known for their intelligence. For example, Varanid lizards have been proven to possess the ability to count (at least up to the number 6) from various feeding experiments. Intelligent, powerful and deadly? A successful recipe for an age old fascination.