George

George is a snake that was caught by Hermes. He is immortal, though he is not a Monster. Demigods and Gods can hear him in their heads. He is always seen with Martha.

Description
George is a snake that loves rats, and is sometimes rude. He is a joker, funnier than Martha. He often teases Percy. They live on Hermes' Caduceus. When it is a phone, he is on the antenna and he also become a note pad when their costumer receives their package to sign their receipt.

The Sea of Monsters
In The Sea of Monsters, Hermes visit Percy near the lake in Camp Half-Blood. He gave Hermes' Multivitamins as a gift for Percy. He often teases Percy just to be on the bright side. After Percy's quest on the Sea of Monsters, when Hermes delivered a letter to Percy, he asks if he had brought him a rat, and as a joke, a guinea pig. (Because Percy once been turned into a guinea pig in Circe's Island)

The Last Olympian
In The Last Olympian, George comes with Hermes to Olympus to deliver a message. George and Martha tell him not to kill Percy, because he bears the Curse of Achilles. He also mentions that he has a laser mode.

He appears with Hermes at the end of the Second Titan War, whispering his condolences, "Luke, poor, Luke" He remains silent when Hermes talked to Percy, which is unusually unlike him.