Korean legends speak of Imoogi—enormous pythons believed to be juvenile dragons. It is said that the Imoogi lived in water or caves, and had to survive for a thousand years before they could ascend to heaven and become true, fully-formed dragons.
Although it existed in South America and not Korea, there was a python of such gigantic proportions that we might mistake it for a young dragon. TheTitanoboa was roughly 46 feet (14 meters) in length and weighed over a ton. It constricted at a force of 400psi, which is like having 1.5 times the Brooklyn Bridge on top of you, and it could swallow a human without even showing a bulge. They went extinct long ago, but we like to think that they ascended to dragon-hood.