Encounter with Hercules
Many years later, Ladon encountered the demigod Hercules, who needed to obtain a Golden Apple from the Garden for the second last of his Twelve Labors. Ladon, however, was too powerful for Hercules to defeat. Because of this, the demigod went to the Titan Atlas to get the apples for him and in exchange, would hold the Sky on his shoulders until he returned. Atlas readily agreed and went past the dragon to get the apples, but when he returned, the Titan saw a chance to escape his punishment. Atlas offered to deliver the apples himself to King Eurytheuses. Hercules, however, saw the trick and pretended to agree, but asked Atlas to hold the Sky for only a moment, while Hercules padded his shoulders with his thick Nemean Lion's Pelt. This seemed reasonable to the Titan, who took the Sky back, but Hercules simply took the apples from him and left, leaving an outraged and infuriated Atlas to endure his punishment once again.Luke tells of how the dragon gave him his scar during his quest (two years earlier) to retrieve a golden apple from the Tree of the Hesperides. Luke failed the quest but did manage to take one of the dragon's claws that is now in the Big House Attic.
Ladon is first seen when Zoë distracts him while Thalia and Percy sneak by to get to the Mountain of Despair. He is loyal to the Hesperides and is trained to guard the Tree of the Hesperides from anyone. He is trained so well that he does not leave the Tree even when baited. He is partly the cause of Zoë Nightshade's death due to his poisonous bite combined with Atlas' finishing blow. One of his claws, being taken by Luke, can be found in the attic of The Big House which holds other spoils of war and the body of the former Oracle.
Ladon is referred to when Percy says that the latter had faced dragons with so many heads that "if you stopped to count them you'd be pretty much dead".
Ladon is described in The Titan's Curse as being terrifying, enormous, with one hundred heads, "like a hundred pythons had been fused together". His serpentine body is thicker than a booster rocket, and his bright scales shimmer like copper. According to Percy, Ladon's breath smells like acid, making the demigod's eyes burn, his skin crawl, and hair stand on end. He describes the stench of it being similar to that of a dead rat, but "a hundred times stronger".
- According to Hyginus' Astronomy, Ladon is actually the constellation Draco.
- Ladon was the one that gave Luke Castellan the thick scar on his face.
- Along with Kampê, and Cerberus, Ladon is one of the few monsters that Percy is too terrified to engage in combat.
- Ladon is, quite possibly, the most powerful son of Typhon and Echidna, since even Hercules could not defeat the mighty dragon.
- He is similar to his brother Cerberus, in that both monsters are used by the gods for good rather than evil; they also both guard specific important mythological locations: Ladon guards the tree in the Garden of the Hesperides, Cerberus guards the Underworld.