Smaug Is Nothing Compared To LotR's Most Terrifying Dragon
If you thought Smaug was the deadliest dragon in Middle-earth, you have no idea how wrong you were.
At the time of the events of The Hobbit, the dragon Smaug was one of the most powerful and fearsome creatures in all of Middle-earth.
In terms of power, he was not much inferior to Sauron himself, and Gandalf was afraid that Sauron would form an alliance with the dragon, then the chances of defeating them would be close to zero.
Smaug destroyed the great human city of Dale and ruined the entire dwarf kingdom all by himself, so he certainly can't be called weak. But he was far from the most impressive member of his race.
Dragons were created by Morgoth aka Melkor, the teacher and master of Sauron. He created these fire-breathing creatures in ancient times, when all of Middle-earth was shaken by his wars with the rest of the Valar.
One of the first wars was with the mighty elves of the Noldor. Melkor soon realized that the orcs alone could not defeat them, and he brought forth the first fire-breathing dragon.
The first dragon was Glaurung. He could not yet fly, but was huge, could breathe fire and used magic.
It can also be said that the spirit of Maya was enclosed in Glaurung's body, making him even more powerful. The next dragon, though not the first, was the most intimidating and so huge that it was hard to imagine its dimensions.
Ancalagon the Black was the greatest of the flying dragons. He became Morgoth's trump card in the war against the other Valar.
This dragon was so large that it covered the sky and was the size of a mountain. When the Valar first saw him and the other flying dragons that Ancalagon led into battle, they were terrified and fled.
Together with smaller flying dragons, he fought a decisive battle during the War of Wrath and was able to destroy most of enemy's army.
Although, Earendil and a large flock of eagles soon arrived and pecked at the mighty dragons, destroying them. After dying, the mighty Ancalagon fell upon the citadel of Melkor, destroying its towers.
It was the descendants of Ancalagon who survived and bred in Middle-earth even after Melkor was defeated and banished from the world.
In particular, one of the heirs of Ancalagon's greatness was the great Smaug, who lived in the north of Middle-earth near Dale.