Poseidon is a deity in Greek mythology, commonly known as the god of the sea, earthquakes, and horses. He is one of the twelve Olympian gods and is often depicted wielding a trident, symbolizing his dominion over the sea. Poseidon plays a significant role in Greek myths and is considered the brother of Zeus and Hades. His influence extends beyond the ocean, encompassing storms, earthquakes, and the creatures of the deep. Poseidon is a powerful and sometimes capricious figure in Greek mythology.