Dragons don't exist today, not in the flesh, though may they might once have, if you believe the stories.
Because every culture in the world has myths or legends or tales of some kind about things that might be dragons.
St George slayed a dragon, they say, and sea serpents lurked (or still lurk) in Loch Ness and Okanagan Lake.
Dragons, sea serpents, wyverns, and wyrms... come see some of those that might have lived, once upon a time...
Sometime in the 19th century, an intrepid explorer named Sophia Shalgrave (who was also widely rumoured to be a mad scientist) journeyed across the world in search of dragons and other creatures long thought to be mythical. The Compendium Dracorum (a natural history in three volumes) was the result of her first journey. No known complete copies remain, but some of the text and most of the original illustrations were preserved by one of her descendants.