
Luke Castellan, who used the venom to poison Thalia's Pine Tree.
Elder Python Venom is a venom derived from the Elder Python monster. According to Chiron, the Camp Half-Blood activities director, the poison originates from the depths of Tartarus.
Percy Jackson and the Olympians[]
The Sea of Monsters[]
Luke Castellan uses the venom it to poison Thalia's Pine Tree, thus forcing Camp Half-Blood to issue a quest to retrieve the Golden Fleece (the only thing that can heal it) from Polyphemus' Island. The Golden Fleece not only heals the tree of its poison, but restores Thalia Grace to life as well, giving Kronos another chance to control the Great Prophecy.