List of characters in the Camp Half-Blood series
Ophiotaurus - A half-cow/half-snake monster. It is an ancient monster that could bring down the gods if it was slain and its entrails were sacrificed. It was nicknamed Bessie by Percy Jackson who initially assumed it was female, although Grover later informed him that it was a male. Percy saved it from a trawler's net after being fetched by the Hippocampi.