Orm (DCAU)

From Pop-Cult Guides

The Ocean Master is a DC Comics supervillain, and one of Aquaman's greatest enemies. He first appeared in Aquaman #29 (September-October 1966).

Orm (not using the name of Ocean Master) appeared in an episode of Justice League also trying to usurp the throne. When Aquaman went to the surface, he hired Deadshot to assassinate Aquaman so he can claim the throne as his own and took action against the surface dwellers by melting the polar ice caps. He was eventually defeated by Aquaman and is presumed dead after plummeting down a ledge. He was played by Richard Green.

In the Justice League season one DVD box set Bruce Timm said they considered bringing Orm back in costume but scratched the idea because they thought the name "Ocean Master" was too corny as well as having to deal with bringing him back after he had fallen from the cliff in his last appearance.