system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] What are dragons, and how powerful are they?

Smaug could drive out the dwarves from a well defended mountain fortress, and the most powerful dragon's fire is capable of melting lesser Rings, but where do dragons stack up with other high tier LotR being like Maiar and Balrogs? Who created dragons and why?
gpt
There isn't a very good answer to this.  Tolkien was not precise when it comes to things like power levels and the like.  We are never told just how dragons were created but it was done by Sauron's old boss the original dark lord Morgoth in his evil fortress during the First Age.  One theory is that the first were Maiar put into flesh, basically evil version of the wizards that then had a bunch of kids. The Balrogs were Maiar that got stuck in that form as they became evil.  Falling from grace in Middle Earth means losing your shape shifting abilities.  From the circumstantial evidence we have, the dragons do seem to have done better fighting the Elves than Balrogs did, though both of them were certainly heavy hitters, and at least some balrogs took orders from the most powerful dragon.  Supporting that is the fact Morgoth made them because he was losing the war.  For Smaug, he was very powerful but almost certainly less so than his forefathers.  One of the main themes of the legendarium is that the world was in decline as it became less magical and more mundane.  Part of what made Aragorn so great was that he was a throwback to a better and more magical time for his people, even if he wasn't an eight foot tall orc slaughtering machine like the King that led the fight against Sauron in the Second Age.