Poseidon

 Poseidon is one of the main Gods in Greek Mythology, he is the god of the seas, horses, and water. He is the brother of Zeus and Hades.

Appearance
Poseidon has light blue skin and dark blue hair. He wears a crown with a starfish on it and a pearl necklace with a pink starfish pendant. He has a mustache that moves around on it's own.

Role In Mythology Island
Zeus eventually reveals that he is going to overthrow Poseidon and Hades and rule all of Poptropica. Poseidon will give you his trident, which will aid you in battle with Zeus. To reach him, you must go to the Grove of Temples. In his temple, use the starfish as an offering to enter his realm. Go to his beach, and swim down into the ocean maze. Hercules must move the rock that blocks the entrance.

Role In Super Villain Island
He also appears as a minor character in Super Villain Island, where he rises out of the sea to give you his trident once more so you can defeat Zeus, his brother.

Trivia

 * Poseidon appears much smaller in Super Villain Island than Mythology Island, though being a god, he is able to change size at will.