In Greek mythology, the Ophiotaurus was a creature that was part bull and part serpent.
Its sole reference is found in Ovid's Fasti (3.793 ff), where the creature's entrails were said to grant the power to defeat the gods to whoever burned them. The hybrid was slain by an ally of the Titans during the Titanomachy, but the entrails were retrieved by an eagle sent by Zeus before they could be burned. The creature emerged from Chaos with Gaia and Ouranos.
The Ophiotaurus reappears in the third book in the "Percy Jackson & the Olympians" series, The Titan's Curse. Percy Jackson saves it in the middle of the night, when he was warned by his favorite pegasus, Blackjack. He first thinks it is a female and names it "Bessie". The Ophiotaurus thinks that Percy is his protector. Later, the creature is brought to Olympus via a magic water bubble and is put under the care of Percy's father, Poseidon. The Ophiotaurus was the creature that Artemis tried to kill before the Titans got a hold of it. Legend goes that if someone slays the creature and burns the entrails in a fire, then they have the power to overthrow the gods. It reappears in Battle of the Labyrinth and The Last Olympian, but as a small part in Percy's life.
