Neptune, the Roman God of the sea, carried a spear called a trident. Neptune is most commonly depicted standing with his trident in his right hand. The trident was said to have magical powers, which he used to manipulate the sea.
Neptune is not only the God of the sea, but he is also the patron of horse racing. Roman mythology states that Neptune produced a horse from his trident, which was one of the ways that chariot racing began. To represent this feat in mythology, Neptune's symbols include both his trident, which looks like a three-pronged spear, and a horse.