were used for longitude and latitude which leads to the Sea of Monsters. They are seen again in The Tower of Nero. In the film adaptation, the Gray Sisters are portrayed by Mary Birdsong, Yvette Nicole Brown, and Missi Pyle. Harpy – Winged spirits of sudden, sharp gusts of wind. They were known as the "Hounds of Zeus" and were dispatched by the god to snatch away people and things from the Earth. Three Harpies work in Camp Half-Blood as "the Cleaning Harpies" being allowed to eat any camper who stays in Camp Half-Blood past noon in the last day of the summer without completing their form or if the camper is caught sneaking out of their cabin at night. In The Titan's Curse, it is shown that there are some Harpies that are on the side of the Titans. In the film Percy Jackson: Sea of Monsters, a harpy (portrayed by Camille Atebe) worked as a barista at a coffee shop with a Hekatonkheires. Aello – A Harpy whose name means "storm swift". She is a member of Camp Half-Blood's "Cleaning Harpies". Aeolus' Harpies - In The Lost Hero, several unnamed harpies work for Aeolus. They construct a floor in the main studio for Jason, Leo, and Piper to walk on. Mellie does not like them because the harpies are mean sudden gusts, whereas the aurae are all gentle breezes. Celaeno – A Harpy whose name means "the dark". She is a member of Camp Half-Blood's "Cleaning Harpies", and is also known as Podarge (which means "fleet-foot"). Ella – A Harpy who appears in The Son of Neptune. She has red hair and feathers, grey eyes, and a bony structure. She has extensive knowledge about the Romans and their culture. Ella is very valuable to the enemy side as she might have knowledge of several scrolls of prophecies. She has memorized a lot of books, and often recites a few prophecies from the Sibylline books that Octavian desperately wants. It is mentioned towards the end of The Son of Neptune, that Ella needed to be hidden from Octavian because of this important knowledge. She was one of the Harpies who was trying to torment the blind psychic Phineas. Near the end of the book, it is revealed that Tyson has a crush on Ella and that she has a crush on Tyson. Because of this, Ella remains with Tyson