His first animated appearances were on the Marvel Super Heroes Show, which aired in syndication in 1966 and featured five of Marvel's superheroes starring in their own series each one consisting of 13 episodes (separated into three 7-minutes long segments). This show had very limited animation, and was composed almost entirely of actual comic book panels with a voice-over; basically an early version of today's motion-comics. The Leader here was voiced by Gillie Fenwick (who also voiced other characters on the show, most notably Baron Zemo in the Captain America segments) is featured in the Incredible Hulk segments; he appears in a total of four episodes and is one of the few recurring villains on the show (the only other one who comes to mind is the Chameleon, who appeared in two episodes, but each time he was actually working for the Leader).

He first appears in the episode "A Titan Rides the Train", where he sends his newest creation, the Humanoids (super-strong, virtually invulnerable plastic creatures) to steal all the nuclear devices in the world. One such device, invented by Bruce Banner is to be moved to another base by train. The Leader sends one of his Humanoids to steal the device, but he didn't count on the Hulk being on the train as well. After a short fight which the Hulk manages to win, he turns back into Banner and is accused by Major Talbot of sabotaging his own invention. The device is then scheduled to be tested on Astra Island, but the Leader learns of this from his spy the Chameleon and sends a horde of Humanoids to be sure the Hulk won't win again. On the island, Banner turns into the Hulk and starts fighting the multitude of Humanoids but it seems to be an endless battle. Major Talbot asks for back-up, and as soon as more soldiers arrive on the island the Hulk, covered by the Leader's robots falls off a cliff into the water below.

The Leader calls back his troops, and the Hulk turns back into Banner and is carried by the waves until he is found and rescued by a Communist ship. Aboard, the captain recognizes him and takes him as hostage back to their country, where a military commander forces him to work for them, until Banner becomes the Hulk yet again and defeats the entire army. The first act of the episode also features a short flashback with the Leader's origin (with the accident that gave him his abilities mentioned to have been because of his own carelessness).

The Leader returns in "Micro Monsters". Here he has found a way to shrink his Humanoids to microscopic size, and then return them to their normal sizes. Banner and Talbot are sent once again to Astra Island to test the Absorbatron (the previously unnamed nuclear device from the episode mentioned above), not knowing the island has already been covered with the Leader's microscopic robots. The Humanoids grow and try stealing the device, but Banner turns into the Hulk and fight them again. This time however the Leader is ready: he has equipped his robots with knockout gas which affects the Hulk and renders him harmless; now both the Absorbatron and the Hulk are in the Leader's hands. Hulk is now a prisoner in the Leader's underground laboratory, where the latter starts studying the Hulk, wishing to learn the secret of his strength so that he could duplicate it - or at least control it. However the Hulk breaks free and starts destroying the Leader's lair (including Banner's Absorbatron) and manages to escape before his secrets are revealed. Soon afterwards the Leader is contacted by his clients, who are blaming him for the loss of the nuclear device. The Leader however promises them an even more powerful weapon - a gigantic Humanoid, who is sent in the dessert to destroy the nearby missile base as a test. Nothing can stop the giant robot, not even the Hulk, who isn't back at full-strength yet. General Ross then orders to launch their most powerful missile, which manages to topple the Humanoid; the Leader sees all this and not wanting his creation to be studied by his enemies causes the robot to self-destruct.

In the next episode ("Brawn Against Brain"), the Leader is briefly seen in the shadows contacting the Chameleon, ordering him to infiltrate the rocket base and learn the secrets of Banner's Gamma Bomb.

The episode "Within This Monster Dwells A Man" marks the Leader's final appearance on the show. This time, he has constructed a machine to scan the world in order to find the Hulk - but everytime he uses it, he only finds Bruce Banner. Banner wanders onto a military riffle testing range, and a stray bullet hits him, triggering his change into the Hulk. The Leader then transports the Hulk to his base, by turning him into electro-waves, and operates him to save his life. He uses a Gamma laser to remove the bullet from his head, but also plants a device which he would later use to control the monster. Once the Hulk awakens, the Leader tells him he has saved him and therefore he owes him his life; he plans on making Hulk the leader of his Humanoid army but Hulk declines the offer, mentioning he refuses to work for a creep. He runs amok inside the Leader's lair, until he is subdued by Humanoids disguised as statues.

The Leader then reveals that the device he planted inside Hulk's head allows him to impose his will on the monster and after performing a series of tests on Hulk to learn his limits, he explains he has a mission for him. Using his telescopic cameras, the Leader has learned that there was life on the Moon, and has also noticed a strange creature there which he named the Watcher. Furthermore, he has managed to track the watcher back to his home planet, and discovered the entire planet is filled with scientific wonders - he plans on sending the Hulk there to retrieve one of these items, the Ultimate Machine. Hulk is teleported to the Watcher's planet with the speed of thought, but before he can fulfill his mission he is confronted by a lizard-like being which apparently came there for the same device. The fight ends when the Watcher teleports the lizard back to its planet after seeing the Hulk is its superior. The Watcher then allows Hulk to take the Ultimate Machine but warns him against using it. Once the Hulk returns, the Leader takes the device - apparently a helmet that contains vast knowledge from all over the Universe - and tries using it, but it is too much for him and he pretty much drops dead. The Watcher then appears but only to take back the device.

All in all, the Leader's first animated appearances were pretty good - the stories are more or less faithful adaptations of the classic comics, and I find them entertaining enough.

In 1981 the Hulk received a new animated series, also entitled The Incredible Hulk which aired on NBC alongside the second season of the Spider-Man and his Amazing Friends animated series. Here the Leader was voiced by Stan Jones and only appeared in one episode, "Punks on Wheels". In this story, Leader recruits a motorcycle gang to steal a shipment of Vibranium - mentioned to be a powerful explosive - from the Gamma Base. Along the way the bikers take Bruce Banner, Betty Ross, Rick Jones and Rita (daughter of a restaurant owner and Rick's girlfriend on this show) as hostages, bringing them back to the Leader's lair. Here the criminal madman with a Gamma-charged brain plans on using a psychic nullifier to make them his slaves. Banner soon turns into the Hulk, defeats the bikers and ends the Leader's plot by detonating the containers filled with Vibranium. The Leader tries to run away but is apprehended by the army, which was warned about his plans by Rick and Rita (who managed to escape earlier). Overall this was a pretty good episode and this version of the Leader was pretty cool - his design looked good, except maybe his purple uniform. He was also depicted as having some limited telekinetic abilities, something I don't remember him doing in any of his other animated appearances.