Imperial Rome had the most amazing war machine of its time. But even Rome had to face its dragons.
During the Punic War, (264-241 BC) the Roman General Marcus Atilius Regulus was leading Roman battalions against troops from the city of Carthage. Regulus came to the River Bagradas and encountered something he wasn’t quite expecting. A hundred feet of giant serpent rose up out the river, its eyes glowing like lanterns.
The thing must have been scary because a Roman general with legions of the best army in the world behind him opted for a strategic re-alignment of priorities. That is, he thought it best to try to ford the river at another place. Before they headed off to find a better spot, the snake disappeared.
But when they sent the first guy over, the soldier vanished under the water with a scream. Sneaky bastard.
The snake ate five or six soldiers, armor included, before Regulus decided to treat a snake the size of a city like a city. He hauled out the ballistae, catapults, and started hurling rocks at it. Once the thing was dead, he had the soldiers pull it out of the water. 120 feet, this thing was.
Regulus had it skinned and presented the skin to the city of Rome, where it was displayed in a temple on Capitol Hill. Unfortunately, it disappeared around 133 B.C.