Sea Leopard is from a legendary race that resided in Antartica called the Ancients that mastered telepathy. Sea Leopard would come into conflict with Namor and other Atlanteans over the contents inside a sunken ship called the Endurance. Sir Ernest Shackleton led an expedition to the South Pole and landed himself in a place called Palmer Land where he discovered a mysterious ore that caused metals to liquified. Shackleton and his men loaded the Endurance with this anti-metal for 281 days but the large quantities of metal began to melt the metal structures on the ship. Shackleton and his men abandoned ship and the Endurance sank underneath the ice. Sea Leopard would protect the mysterious ore on the Endurance at any cost.
Namor learned that Leon McKenzie, the grandson of Leonard McKenzie launched an expedition to the South Pole to find the Endurance and its top secret cargo. Phoebe Marrs told Namor that she sent another expedition to look for the Endurance as well. Namor told Phoebe that her team was in danger because Attuma and his horde was residing within the city of Old Atlantis near the Endurance's location. Namor and Andromeda went to the South Pole to stop Leon McKenzie from stealing the contents of the Endurance. Andromeda went to the city of Old Atlantis and called out her father Attuma. Her father appeared from the shadows but collapsed and discovered that he was taken down by Sea Leopard. Namor found the Endurance when Sea Leopard appeared holding the motionless bodies of Andromeda and Attuma.
Namor attacked but Sea Leopard was able to use his telepathy to predict Namor's actions during battle. Namor used his own telepathy to control a killer whale to grab Sea Leopard and take him away deep under the ice. Leon McKenzie disguised as Black Moray found the Endurance when he was approached by Sea Leopard. Black Moray's attire was able to block Sea Leopard's telepathic probes so Sea Leopard told McKenzie that he can get the anti-metal as long as he can get Namor to bow down and become his lifelong slave. Attuma and Andromeda would battle Sea Leopard while Namor confronted Black Moray. During the fight with Namor, Black Moray set off a giant explosion on the Endurance. Sea Leopard bested Attuma and his daughter in combat when he saw Black Moray from a distance. Black Moray told Sea Leopard that the Endurance was destroyed and Namor was dead. However, Namor was donning Leon's suit and was able to get close enough to Sea Leopard to strike him with a thunderous punch. Andromeda and Attuma also assisted Namor in taking down Sea Leopard. Attuma told Namor that his people would impose a suitable punishment for Sea Leopard.
Sea Leopard would appear sometime later with the Fathom Five and attack the surface world. Sea Leopard and the Fathom Five would be defeated by Ms. Marvel and members of the Thunderbolts. The current whereabouts of Sea Leopard are unknown.
Powers & Abilities
Sea Leopard is from the legendary race called the Ancients and has some telepathic abilities. He can probe the minds of anyone in close proximity and predict their movements. Sea Leopard can breathe underwater and has a degree of superhuman strength and speed. He also possesses claws on his hands and a tail he can use to strike his opponents with a powerful blow. Sea Leopard's tail is strong enough to snap the spine of small cetaceans and sharp enough to puncture a person's body.