I'm from Romania, a country where you fill like you are in a trash can in urban zones, but feels like a fairy tale in rural zones. In school we learn about fairy tales (which is a species of very important literature). Many of them have an unknown author, being transmitted from generation to generation.
I remembered randomly about this, and that in many of them the antagonist is something called "zmeu". It is very similar to a dragon, but the fairy tales never describe him physically, although there is another story about something called "balaur cu sapte capete", which translates to "monster/dragon with 7 heads", which describes the same thing as the "zmeu". Now this is very similar to the Hydra from Greek mythology, which was a giant dragon-like reptile with 9 heads instead of seven.
In one of the stories, when the hero cuts off a head of the "zmeu" with his sword, it regenerates. The Hydra grows 2 heads when one is cut off. There is also the Chinese dragon we all know, the Hebrew Leviathan, the giant sea serpent from the Bible. It is clear that all those myths have a common ancestor, a source of inspiration, something they tried to symbolize trough them.
Some say that it is a representation of humans' fear of dangerous reptiles like snakes, crocodiles, poisonous lizards, etc. But I think there is more: that the people who thought about these creatures centuries and millennia ago wanted to illustrate an idea. Maybe they wanted to show a human negative trait like greed or envy (which is what I read about Leviathan), or evilness and cruelty. What do mythologists think?