Oceam Master was Aquaman's fully human half-brother, the son of Tom Curry (Aquaman's father) and a woman named Mary O'Sullivan. He becomes a villain because he grows jealous of Aquaman and how he becomes King of Atlantis. Ocean Master is full human. He later has amnesia and disappears. Several years later, the self-named Orm Marius reappeared as the Ocean Master, a high-tech pirate who initially attacked ships but quickly moved on to causing natural disasters in order to hold the world at ransom. 