After killing two creatures with a treasure chest, pirates bury it on Amzot when the Herculoids approach; Dorno is captured and held hostage.
An alien spacecraft hovers over Amzot, dropping mechanical pods onto the planet. Meanwhile, Dorno, Igoo and Gleep, on a mission to get firewood, see the robotic pod creatures as the pods open up and start attacking the trio.
Krokar, leader of the Beaked People, stages an invasion on the Winged Monkeys, purposely letting one escape so he can capture Zandor and rule Amzot.
After being woken up by a bird, Zandor investigates Marcon and the Mole Men's plans to invade the surface world, saving a condemned prisoner in the process. Meanwhile, other Mole Men are attacking the Herculoids.
A group of spider-like creatures kidnap Dorno, then try doing the same with Tara. Gloop saves her while Gleep blows a horn beckoning the Herculoids to action. Zandor briefly frees Dorno with his shield but is soon captured with Dorno. After a stalemate, Zandor calls the Herculoids to action for one concentrated attack.
Andropon and his robots invade Amzot, where the Herculoids easily defeat them. After Andropon continuously threatens to build replacement robot armies (and Zandor continuously vows to defeat said armies), Andropon pits his top warrior Ogron against Zandor and Zok.
Trained machines break Mekkano out of an intergalactic prison, where he vows to destroy the ones who put him in prison: Zandor and the Herculoids.
After destroying the last wild creature of Kyanite, Neron and his gladiators capture Tundro. Zandor and Zok, followed by the rest of the Herculoids, arrive at the arena to rescue Tundro and fight the gladiators.
Oton, leader of the Time Creatures, has determined that in order to rule Amzot in the future, he has to change its past, starting with destroying the Herculoids and altering time in his favor.
A terrible wind storm is raging on Amzot. However, Zandor notices that winds on the left side of a canyon are aiming right, while winds travel in the opposite direction on the right side. Zandor and the Herculoids investigate, and discover Konar is destroying Amzot's atmosphere to replace it with his own. Konar sends his henchmen, who are either killed or injured by the Herculoids. As Zandor confronts Konar, Konar brings out the giant Zorbots to take on the Herculoids. Zandor chooses to surrender in order to destroy the wind machine from within and, when successful, battle the Zorbots.
A lightning storm causes a nest of giant ant eggs to hatch. The giant ants cause havoc and destruction and Zandor and the Herculoids must put an end to them.
Amak and the Amatons come to the planet and place control collars on some animals. When their efforts to enslave the Herculoids fail, Amak tries to kill them. Gloop and Gleep save the day by turning Amak's stun turret on him, causing his ship to crash.
The story starts with Zandor knocked out by the Laser Lancers and the Herculoids coming to the rescue. Magoth and the Lancers send a new wave of attackers which the Herculoids repel, but it is a ploy to take Dorno and Tara hostage. With Gleep's help, they seal off the tunnel the Lancers used to sneak up and repel them once and for all.
A ship crash-lands on Amzot with a sole occupant on board. Zandor offers assistance and the passenger turns out to be a Mutoid, a race who can change their appearance to anything. The Mutoids plan to use Amzot as a launching site for their missiles to fool their enemies. Can Zandor and the Herculoids stop them in time?
Sta-Lak returns to Amzot seeking vengeance and equipped with robot duplicates of Igoo, Zok, and Tundro. He captures Dorno, Tara and Zandor and the others are forced to go into his volcano lair. The robot duplicates prove no match to the originals, even though the robot Igoo can spin at high speeds and has multiple arms, and the robot Tundro can fly. Sta-Lak enters a bubble and flees into a volcanic lava hole.
Tara is captured by the Reptons, who place her in a mind control device to make her their evil queen. She orders her people to destroy Zandor and the Herculoids, who beat them and go to rescue Tara. The Reptons send the Destructo Bats after them, but they escape, recover Tara, free her from the machine's influence, and destroy the Reptons' underground lair.
Amzot is being bombarded by the planet Luvanuum. Zaygot and his henchmen are trying to destroy Azmot. The Herculoids travel to Luvanuum in a ship captured from Sarco. When they land, their ship is destroyed and they are attacked by winged sentries with deadly laser beams. The Herculoids destroy Zaygot's base and he escapes—they use Zaygot's ship to return to Amzot.
Zandor and Dorno rescue a man floating in the river who says he is from Gravite Island and tells them that a villain has taken over the island. The Herculoids go to investigate and are attacked by giant gravite creatures. The creatures are being created by Lotak, who wants the village because of its large deposits of gravite. Zok destroys the machine Lotak uses to make his creatures and Lotak is destroyed when his energy ray backfires.
