Argus

Argus is the many-eyed security guard at Camp Half-Blood.

History
He is first seen by Percy Jackson when he partially regains consciousness after the Minotaur battle. He has blue eyes all over his body and supposedly has one on his tounge. This is a speculation as to why he doesn't talk, as he doesn't like to show it off. When he rolls his eyes it looks like his whole body's swirling. Besides guarding the camp (which he only does in emergencies), he usually drives heroes out to Manhattan at the beginning of their quests. In The Last Olympian, he is one of the few defending the camp.

Trivia

 * Argus is based off the monster Argus Panoptes who is the favourite of Hera.