According to Greek mythology, Poseidon was the god of the sea, earthquakes and horses. He was best known as the god of the sea, and sailors claimed to rely on Poseidon for protection and safe passage on their journeys. His parents were Cronus and Rhea. He had two brothers named Zeus and Hades, as well as three sisters named Hestia, Hera and Demeter.
Poseidon was also worshiped by some as a fertility god. His main weapon was a trident he used to cause earthquakes. His primary mode of transportation was a horse-drawn chariot. Poseidon was known for being hot tempered. He was vengeful and often resorted to violence. Poseidon had a vendetta against Odysseus after he blinded his son, the Cyclops Polyphemus, so Poseidon delayed Odysseus' return home from the Trojan War for years. His vengeance included causing a storm that shipwrecked Odysseus.
Poseidon had the power to shape-shift, which he used to trick others into getting his way. He tried to romance his sister Demeter, but she refused by turning herself into a mare. Poseidon reacted by turning into a stallion and continuing to pursue her. They ended up having a horse-child named Arion. Poseidon had many other children, including Orion, Polyphemus and Pelias.