The Bible mentions a dragon in Revelation chapters 12, 13, 16, and 20. Revelation 20:2 identifies the dragon: “He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years.” The Bible is not teaching that dragons ever truly existed. Rather, it is only comparing Satan to a fire-breathing monster.
It is interesting to note, however, that nearly every major ancient culture has myths and legends about giant reptiles. How would these civilizations, continents and millennia apart, all come up with legends of giant reptilian creatures? Classic evolutionary theory claims dinosaurs existed millions of years before human beings. Dinosaur fossils were not discovered until thousands of years after the myths of giant reptiles began.
Some suggest that humans and dinosaurs might have co-existed. Scripture mentions two creatures that seem remarkably similar to the dinosaurs, the leviathan and behemoth, in Job chapters 40—41. Some young-earth creationists believe the “dragon” myths came from real contact between human beings and dinosaurs. This view holds that all animals were created around 6,000 years ago and co-existed with human beings. That would explain how all human cultures have myths about giant reptiles—because they actually saw them!
Of course, this is not the universal view of all Christians, nor of most scientists. Likewise, the “fire-breathing” aspect of a dragon is most likely entirely mythical. Universal legends of giant reptiles are seen by some as proof of real contact between human beings and dinosaurs or some other creature no longer seen in the modern world.