Morgoth didn't have the abbility to create things out of the blue (the only one who can do that is Iluvatar). How do you think he created dragons?
I haave a couple of theories:
1) Dragons are, like Balrogs, corrupted Maiar. But I don't think this is possible.
2) Morgoth used his own essence to make them, hence why they're evil and greedy by nature.
3) They were once Yavanna's creatures but then were corrupted by Melkor.
3) They were once Yavanna's creatures but then were corrupted by Melkor.Perhaps Melkor's experiments that brought about the dragons began when large, prehistoric saurians still existed. The bodies of his experimental creatures might have been made to host corrupted Maiar or other spirits of fire.
Perhaps he started with common garden lizards and bred them for size and intelligence, and magicked wings on.
Humans could probably do the same, if they were willing to spend ten thousand years at the task.
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