Peleus

Peleus is the dragon that guards and protects the Golden Fleece that hangs on Thalia's tree. He is probably named after a king who's wedding Eris was not invited to, and she threw the golden apple that started the Trojan War.



The Sea of Monsters
Since Percy, Grover﻿, Annabeth and Clarisse brought back the Golden Fleece from Polyphemus' Island to put on Thalia's tree, they had to find a suitable guardian. Peleus, a baby dragon at the time, was chosen. Chiron and Argus fed and looked after him until he was able to care for himself and the Fleece.

The Last Olympian
When Rachel forced Blackjack to fly her to Camp Half-Blood, Percy was worried that she might get attacked by Peleus since she was a mortal.

Trivia

 * Peleus is named after the father of Achilles.
 * Known as at least as thick as Thalia's pine tree.