In The Lord of the Rings, Middle-earth is no stranger to enormous creatures. From the Balrog of Moria to Shelob in Mordor, Tokien's world is filled with oversized monstrosities that terrorize those unfortunate enough to cross their paths. One such creature was the dragon Smaug, who claimed Erebor and all of its gold from the Dwarves with relative ease. Despite Smaug's gargantuan size, the dragon was nowhere near the largest creature ever to roam Middle-earth, as another member of his species takes that trophy by a landslide.
The Hobbit never provides a specific size for Smaug. However, from J.R.R. Tolkien's drawings and notes, it's assumed the dragon's depiction in the Peter Jackson trilogy is pretty accurate. Smaug was able to fit in the door to Erebor but was also large enough to destroy most of Lake-town when he fell from being shot. Being one of the few dragons left in Middle-earth, it's fair to assume Smaug was the biggest dragon to roam the world during Bilbo's lifetime. However, through the history of Middle-earth compiled in The Silmarillion, it's clear that Smaug would have appeared little more than a rodent in comparison to Ancalagon the Black.
Updated on September 4, 2023, by Ajay Aravind: Tolkien's Lord of the Rings isn't limited to the titular trilogy — on the contrary, the fictional universe of Middle-earth is extremely vast and culturally diverse. Countless events have transpired over the course of history, splitting the timeline into the First, Second, Third, and Fourth Ages. Although most of the dragons appeared during the First Age, these malevolent creatures remained part of the internal discourse for thousands of years after. Dragons come in a wide range of shapes and sizes; some of the earlier ones were even wingless worms. All things considered, however, only one Lord of the Rings dragon deserves the distinction of being the greatest.
Morgoth Created Dragons
During the First Age of Middle-earth, the Dark Lord Morgoth spread terror across the land as he attempted to rule all of Middle-earth. While having the same goals and ambitions as Sauron, Morgoth was far more powerful and an even greater threat to the world. During Morgoth's reign, he bred a series of vile creatures and entities, the strongest of which were the dragons. The first dragon created by Morgoth was known as Glaurung, a wingless worm capable of hypnotizing both Men and Elves. He plays a critical role during the First Age, particularly in Túrin Turambar's tragic hero's journey.
The dragons that followed Glaurung possessed the ability to fly. Although there are only four named dragons in the story, all of them are capable of breathing a fire so hot that it could have melted all the Rings of Power — except the One Ring. Thankfully, Smaug was killed long before the events in The Lord of the Rings, because he would have most likely joined forces with Sauron and made Frodo and Sam's journey almost impossible. However, despite Smaug's incomparable strength, intelligence, and cunning, he couldn't hold a candle to the biggest dragon in Lord of the Rings.
That title belongs to Ancalagon the Black, a truly massive dragon bred by Morgoth in the deepest pits of Angband. His name can be loosely translated to mean "biting storm," a fitting epithet for such a monster. Nobody knows anything about this creature's origins — some fans posit that Ancalagon could have been a transfigured Maia, whereas others suggest that he was birthed from the filth of the world itself. Whatever the case may be, there's no doubt that Ancalagon was Morgoth's most fearsome and formidable weapon. According to Gandalf, however, "not even Ancalagon the Black... could have harmed the One Ring, the Ruling Ring, for that was made by Sauron himself." As such, there are clear limitations to the dragon's powers.
Ancalagon Would Have Towered Over Smaug
Ancalagon's precise height is never given. Still, he is described to be "as tall as a mountain" and could block out the sky as he flew overhead. So, the Men and Elves didn't stand a chance as the dragon destroyed their lands and laid ruin to their armies. Ancalagon the Black made his first appearance during the War of Wrath, a series of battles that would mark the end of Morgoth's malevolent reign over Middle-earth. When the Valar's armies overwhelmed the Dark Lord's multitudes, he decided to play his final move: the release of the dragons from Angband.
Led by Ancalagon, the dragons wreaked havoc upon the forces of the Valar, forcing the Eagles to intervene. Thorondor, the leader of the Eagles and the ancestor of Gwaihir, fought the winged dragons in the sky along with Eärendil's help. The elf-lord arrived "shining with white flame," slayed "Ancalagon the Black, the mightiest of the dragon-host, and cast him from the sky." Ancalagon subsequently "fell upon the towers of Thangorodrim, and they were broken in his ruin." In other words, he was large enough to destroy the three volcanic mountains constructed by Morgoth as well as the surrounding landscape. Thangorodrim was thousands of feet tall at the very least, making Ancalagon exponentially bigger than Smaug.
Smaug's lifeless body was just the right size to obliterate the town of Esgaroth, so he wasn't exactly a small beast. Meanwhile, Ancalagon's fall managed to terraform an enormous chunk of land, presumably changing the geography of the area forever. All these details make the First Age sound like a terrible time to be alive.
Luckily, however, the monstrosities of Middle-earth faded over time. And, with the defeat of Sauron and the Age of Men beginning, the giants of the world would seemingly disappear altogether. That said, fans still remember Gandalf's ominous words — "Far, far below the deepest delvings of the Dwarves, the world is gnawed by nameless things. Even Sauron knows them not. They are older than he." There might well be an ancient monster that dwarfs even Ancalagon the Black.