Colchis Bull

The Colchis bulls are bronze bulls the size of elephants. They were made by Hephaestus, or at least come from his forges, according to Annabeth. They are made from bronze. Their horns are sliver and their eyes are rubies.

The Sea of Monsters
The Colchis bulls attacked Camp Half-Blood. They are defeated by Tyson. They were later used to make the tracks for the Chariot Races.

Powers

 * They are bronze, so it is hard to damage them (as they are metal).
 * They can breathe fire.
 * They aren't hurt easily with weapons (as they are metallic they are usually only dented or scratched).
 * Their skin is burning hot.