How about Black Manta or something lol?
Or the guy they had to fight when they met Aqualad, Trident?
: One of the most feared villains of Atlantis, Trident's downfall came around when Aqualad, teamed with Beast Boy of Teen Titans, discovered his underground lair. Trident had found a way to clone himself, using containers of a nuclear substance he had commandeered off of a supply ship out in the ocean, allowing him to be in multiple places at once. After a scuffle with Aqualad and Beast Boy, the T-Sub, piloted by the remaining four titans and Aqualad's technician friend, Tram, they sealed off the entrance to Trident's cloning area with a few blasts from the sub's seismic blasters.