I remember my grandmother telling me Hungarian legends about dragons when I was little, so I looked into it this morning and here's what I found. In Wikipedia, of course.
"Sárkány (dragon) mythology
Early appearances
Dragons were part of Hungarian culture prior to the 18th century. According to their oldest, universal function, dragons symbolized the unity of the material and spiritual worlds. They were later associated with natural phenomena. They either made or appeased the violent forces of nature. They brought rainstorms and tornados. The rumble of the thunder was the roaring of dragons battling above the clouds, striking the clouds with their tails with crash in the heat of the fight and, as a consequence, causing floods of rain pouring over the Hungarian fields.
Characteristics

A
Sárkány with numerous heads
Though legends offer scant information about the characteristics of the ancient dragons, in some regions it was an accepted that they were born through a transformational process of another being. In the region of
Csallóköz, for example, it was thought that dragons were created from an old pike or a 7 or 13-year-old rooster. As the tales tell, when a pike is laying in the mud for several months, it changed into a dragon. In the rooster's case, a dragon is born when the bird hides around the house for too long;. As a dragon, it can be only lured out by the so-called
Garabonciás, a human with magical qualities, who later uses the beast as a mount.
In other regions, the belief was that dragons can be born from other dragon. The female, after being pregnant for seven years, suckles her son for another seven years. Dragons usually appear in two forms: the first is the rideable, tyrant mount of the Garabonciás, and the other is the serpent-like creature with several fins, long claws and teeth. Their scales can vary between all the colors of the rainbow, and they are so strong that almost no weapon can hurt their skin. They usually live inside hollow trunks, dens, or in the abandoned caves in the mountains.
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Here are two paintings I found. One is by Durer, and the other one from a Fairy Tale book. Dragons seem so prevalent in all cultures that they must have existed. Otherwise, how would so many different cultures have invented the same creature with the same characteristics?