Lustful Passion
Poseidon's passions for women demonstrated itself in his many love affairs, though he was actually married to a beautiful wife named Amphitrite, who didn't seemed to mind his indiscretions. The couple had three children, but he had others with other gods, water nymphs and mortals. He even was attracted to his own sister, Demeter, and created a horse for her.
Greed
Poseidon personified greed, continually seeking more riches for his underwater kingdom. He had palaces on Mount Olympus and in the depths of the seas. Both were laden with gold and precious gems, but he was always seeking more worldly goods. He also was greedy for power, though he was reputedly the most powerful of the gods next to his brother, Zeus. Poseidon vied to have a Greek city named after him rather than the goddess Athena. He often fought with other gods over the possession of countries.
Unpredictability
Poseidon was a symbol of unpredictability, just like the ocean weather. When he was in good temperament, he made the weather fair and the waves calm. But he was prone to tumultuous moods, causing the seas to darken and swell. This resulted in shipwrecks and tidal waves depicted throughout Greek mythology. Sailors often offered libation to Poseidon with the hope to keep him in an even temperament.
Violent and Vengeful
Poseidon was a violent and vengeful god. He could kill at whim and would never let a slight go without notice. He attacked Odysseus for blinding his son, the Cyclopes, even though Odysseus was acting in self defense because Cyclopes threatened to devour Odysseus. He flooded the city of Athens because it did not appreciate the spring of water he made in an attempt to have the city named after him. Poseidon carried the trident, with which he could split boulders and cause earthquakes. When he did not receive payment for building the walls of Troy, Poseidon sent a sea monster to cause harm.
Lover of Animals
Poseidon and his love of animals is detailed in Greek mythology. He is often seen riding a chariot drawn by seahorses. He created these creatures and is believed to have created the first horse to woo Demeter. The dolphin is also a symbol of Poseidon, which he created for the ability to move effortlessly through water.