Sea Leopard
Sea Leopard is a
member of the race called the Ancients. Not much is known about
this centuries old being, but he claims to be the posessor of a
throne (possibly the original Atlantis). For the last 85 years
Sea Leopard had been guarding what he called the Sacred Horde.
The Sacred Horde was a gigantic shipment of Vibranium.
Namor #52- flashback- In 1915 Sir Ernest H. Shackleton lost his ship, The Endurance, on a trip to the South Pole to retrieve a strange ore that melts all metal. The ore melted all the metal holding the boat together. Shackleton and his crew see Sea Leopard blowing a horn surrounded by three blue skinned women. Sea Leopard tells the violator of the sacred horde to come to him. Shackleton runs from him, and actually survives his journey to safety.
Namor #52- Andromeda comes to Old Atlantis to find Attuma, but instead she finds him defeated at the hands of the Sea Leopard. Sea Leopard says he hopes that Andromeda provides more sport than her father did. Andromeda says she will find her ready to overcome a pretender to the throne. Sea Leopard says he is no pretender as he leaps over her and disarms her. Later Namor chases after an embezzler of Oracle Inc, called Black Moray, who is attempting to take the ore that was unsuccessfully retrieved by the Endurance. Namor instead comes face to face with the Sea Leopard as he holds up the defeated Andromeda and Attuma.
Namor #53- 
Namor
charges Sea Leopard, but Sea Leopard bashes Namor's head together
with Attuma and Andromeda. Sea Leopard drops Attuma and Andromeda
as he swims over Namor and bashes him with his tail. Namor
charges Sea Leopard, but Sea Leopard easily dodges. Namor says
that he is fastest in the sea, but Sea Leopard dodges his every
move. Sea Leopard ducks under Namor's next charge and uses his
tail to send Namor flying out of the water. Sea Leopard blasts
through the ice Namor lays on. Sea Leopard says that Namor should
just surrender as he is unaccustomed to the terrain while it has
been his home for centuries. Leopard throws Namor back into the
water, but Namor emerges from the water flying and holding a
large chunk of ice. Leopard dodges the block of ice. Sea Leopard
uses his telepathic powers to ask Namor if he has ever heard of a
race called the Ancients. Leopard can read Namor's thoughts and
can dodge a punch before it is thrown. Namor uses his telepathic
ability to ask a killer whale to pop out of the ground and bite
Sea Leopard. Black Moray tries to sneak aboard the ship to take
the ore when Sea Leopard throws one of the killer whale's ribs to
block his path. Sea Leopard notes that Black Moray's helmet
blocks his mental probe. Leopard asks if he is trying to break
their agreement. Leopard was to a person to worship him for every
ounce of anti-metal. Moray tells Leopard that he can have his
crew, Oracle's crew, and all of Old Atlantis. Leopard says he
wants Namor for his slave now. Attuma and Andromeda return to
fight Leopard together. Andromeda hits high while Attuma hits him
in the chest with a pole. Attuma then directs Andromeda to strike
Leopard while Attuma grabs his foot. While they fight Moray
sneaks off, but encounters Namor. Attuma, Andromeda, and Sea
Leopard hear and feel an explosion from the sunken ship. Leopard
realizes the ship he guarded since 1915 has been destroyed. He
prepares to use his tail to skewer Attuma, but Andromeda jumps in
the way. Leopard sees Black Moray returning. Moray tells Leopard
that the Endurance is destroyed and that Namor is dead. Leopard
grabs Moray and says he has been guarding the sacred horde for as
long as he can remember, and that Namor was to be his slave.
Suddenly Namor bursts from the armor. Namor knew it was the only
way to get around Leopard's powers so that he could hit him.
Attuma grabs Leopard from behind, and Andromeda hits him. Namor
knocks Leopard out. Leopard is in a net it's decided that Attuma
will impose punishment for Leopard.
Thunderbolts vol. 2 #4- behind the scenes
Thunderbolts vol. 2 #9- behind the scenes