Eidolons – A race of spirits that can possess demigods. In The Mark of Athena, the Eidolons work for Gaea. Elephant - The elephants are large herbivores native to Africa and southern Asia. Any elephant that is bred for war is called a war elephant. Hannibal - A war elephant that is owned by Camp Jupiter and often cared for by Bobby. Livia - A war elephant owned by Commodus. In The Dark Prophecy, Livia was present at the rehearsal of Commodus' naming ceremony until she was rescued by Apollo and Thalia. In The Tyrant's Tomb, Apollo makes a claim that she and Hannibal would get along. Erymanthian Boar – A giant boar and servant of Pan who appears in The Titan's Curse. Percy, Thalia, Zoë, Grover, and Bianca first encounter it in Cloudcroft, New Mexico where Grover realizes its potential as a form of rapid transportation. Fire-Breathing Horse – A race of horses bred at the Triple G Ranch for war purposes. Some are shown to pull Ares' war chariot. In The Dark Prophecy, some Fire-Breathing Horses are owned by Commodus. Flesh-Eating Horse – A group of female horses bred at the Triple G Ranch. Some of them tried to eat Percy while he was cleaning the stables. Flesh-Eating Sheep – Carnivorous sheep owned by Polyphemus. They help to guard the Golden Fleece. Described as being a big as a hippopotamus and attacking like piranhas. Giant Badger – A giant badger. In The Last Olympian, it was mentioned that Gleeson Hedge tried to fend off the Giant Badgers and tried to summon Pan to help him to do that. Giant Crab – A giant crab that might be Cancer. Percy fought it in the Princess Andromeda during his mission with Charlie. He defeated it by stabbing the soft tissue on its belly. Giant Eagle – A giant-size eagle that appears throughout The Heroes of Olympus series. The Giant Eagles are mainly used by the Romans for transporting and protecting Roman demigods. Giant Raven - A giant-sized raven. Caligula and Nero use a flock of them in The Tyrant's Tomb to protect Harpocrates due to the ravens hatred for Apollo. Apollo manages to scare them away at first by singing Dean Martin's "Volare", adopting a similar tactic used by Percy to disorient the Stymphalian Birds in The Sea of Monsters. When the ravens return, they are slaughtered by Apollo, Reyna