What if??

[Lalwendë]

Originally Posted by Farael

Morgoth could not create, only corrupt things. So I guess either dragons already existed and he used them for his own means or that there were things like dragons which he perverted into things like Smaug.

It could be that the dragons were corrupted by Morgoth, as their origins are unknown beyond that they emerged from Angband. They could have been extant creatures, corrupted to his needs, but we do know that Morgoth 'bred' dragons. Smaug is said to have been the greatest of his kind so he could have been one of those bred by Morgoth or a descendant of them.

It's worth bearing in mind that Sauron followed Morgoth and so may indeed have had much knowledge of dragons and how to control them - maybe with gold . In any case it is clear that Gandalf believed him to be a significant threat, so we can assume that he at least suspected Sauron would be able to control Smaug.