Aquaman Episode 35 - "The Silver Sphere" by Dennis Marks
At an undersea sulphur pit, a silver sphere appears which seems to have magical properties. Unfortunately it rests right on the land division of two different races, the blue Tortoids and the green Lizard Men. One of the Tortoids claims ownership, so when one of the Lizard Men says it's here, the Tortoid promptly shoots him in the face with a ray gun, stealing the sphere.
This quickly escalates into full-scale war, so guess who arrives to clean this mess up? Of course, Aquaman! After some well-thrown hardwater projectiles, the Sea King attempts to talk some sense into these knuckleheads:
Each race says the sphere is theirs, so Aquaman comes up with a more peaceful way of determining ownership: a series of physical contests, with whoever winning getting to own the sphere for a year. Little do they know, but Black Manta is nearby, watching all this with a plan to steal the sphere from all of them!
When some Manta Men show up blasting, one of the Tortoids saves Aqualad from getting hit. Aqualad then agrees to sub for him in the sphere contest, much to the delight of the shorter, less physically agile Tortoids. The first competition is a race through razor-sharp sea brambles, with the Lizard Man winning after he(?) cheats.
Aquaman informs him that Black Manta has stolen the sphere, but to keep the peace Aqualad should continue with the games so he can retrieve it. The second contest is a wrestling match, with the young man putting the Lizard Man in a vice-like grip until he begs for mercy. Meanwhile, Aquaman tracks down Black Manta, but soon finds himself playing Anastasia Steele to Manta's Christian Grey:
The Tortoids and the Lizard Men discover the sphere is gone, and assume Aquaman has stolen it for Atlantis. Aqualad explains the truth, and they warn him that if Aquaman does not return with it, he will be enslaved to both races. The contest goes on, with Aqualad winning the third competition. Meanwhile, Aquaman frees himself thanks to his finny friends and brings back the sphere, with Manta close behind in his Manta Ship.
With the help of a whale, Black Manta is knocked into the sulphur pit, much to the cheers of everyone. Having won the contest, Aquaman awards the sphere to the Tortoids, who say that they have reached an agreement to share it, to even more cheers from everyone. The End!
This is Black Manta's final appearance on the show, and it's a little sad he is so easily dispatched. The Filmation Manta Men are some of my favorite examples of their visual creativity, I can never get enough of those creepy looking dudes with their worried faces.
The sequence with Aqualad wrestling the Lizard Man is probably the most outwardly violent in the whole series, there's a close up of his rattling tail going limp as he taps out thanks to Aqualad's chokehold. The kid really wanted to win!