Polybotes

Polybotes is one of the giants.

History
He sided with the Giants in Gigantomachy. After the giants lost the war, Poseidon defeated him by riping a part of the island Kos apart and hurling it at Polybotes. This fragment then formed the island Nisyros.

The Son of Neptune
In the end of the book, Polybotes was defeated by Percy Jackson and the god Terminus.