Aquaman’s greatest enemy is the scourge of the seven seas, David Hyde – The Black Manta.
For decades before any information was revealed about who he really was. Even when he committed his greatest act of villainy—killing Aquaman’s infant son, Arthur Jr.—his motivations for such an act were very much a mystery.
The young child who would take the name Black Manta was born in Baltimore, Maryland, near the Chesapeake Bay. One day, while playing by the water as a boy, he was kidnapped by pirates and forced to work as a slave on one of their ships. Abused by his captors for an unspecified amount of time, he spotted a young Aquaman and a group of dolphins in the ocean. He signaled for rescue, but was not seen. He subsequently killed one of his captors, but never forgot how, in his eyes, the King of the Seven Seas had rejected his plea for help. From that day forward, Aquaman was his enemy.
During this time, Manta had given a different account of his troubled childhood. Instead of coming from Baltimore, he was said to have grown up in Gotham City. An autistic child, he was, for reasons unknown, placed in Arkham Asylum. There, he preferred to be immersed in cold water rather than a comfortable bed.
The staff at Arkham, not knowing how to cope with his autism, chose to administer an experimental treatment that would cure him. While it seems his autism was cured, the treatments made him excessively violent. Not long after, he killed the scientist who administered the procedure and escaped Arkham, beginning a life of crime.