Banished from the village by Chief Pondo, Korg wants to get even so he sends an army of animals to attack. He then demands that Pondo step down and appoint him the new chief or he will bring his animals back and destroy the village. Tor, not wanting his friends to be harmed, turns into Mightor and does battle with Korg.

The Tiger Men decide to attack the cave people as their god demands a sacrifice. The Tiger Men capture Tor and to punish him for alerting the others, take him to the arena. Tog needs to get Tor's club before the saber-toothed tiger does him in at the arena.

Sheera is captured by the Bird People while getting water at the river. When she doesn't return to the village, Tor goes in search of her. He turns himself into Mightor and discovers her by the lava pits where she is about to be sacrificed to their god Dogar.

Sheera is kidnapped by one of the Serpent Queen's underlings to be turned into her slave. When Pondo and Tor discover Sheera missing, Tor heads off for help. When he is out of sight he turns into Mightor and returns to Pondo to offer his assistance.

Grok orders Tyrannor, a giant T-Rex, to throw a boulder at the village. He then challenges the village to produce Mightor to fight Tyrannor or he will destroy the village.

The Giant Hunters, an evil group of creatures, come upon Chief Pondo's village and capture Tor and Tog. Fortunately, Tor has his club and is able to turn himself into Mightor and the battle is on.

While the men are off hunting a giant ape appears and captures Sheera. Mighty Mightor returns quickly, discovers what has happened, he goes after Sheera. He finds that the ape yook her to his nemesis, Korg.

Brutor the Barbarian is leading his army of creatures in an attack on the village when they come across Tog and bring him down with one of their weapons. Tor tells Sheera and Li'l Rok to warn Chief Pondo and the villagers of Brutor's plan.

Sheera's mammoth cub, Bollo, disappears and she sets out to find him, unaware that the Tusk People have kidnapped him. Tor and Tog realize that Sheera and Bollo are missing and notice their footprints mixed in with those of the Tusk People. Tor turns himself into Mightor in an effort to save them both.

Sheera is captured by the Cavern Creatures who take her to Kragor. Bollo returns to the village without Sheera and Li'l Rok so Tor knows something is wrong. He discovers that the entrance to the where the Cavern Creatures and Kragor live is open and realizes that they must be to blame for his friends disappearance.

Sheera and Tor hear thunder during a snowstorm and discuss how it's said to be the voices of the Snow Trappers. Li'l Rok doesn't believe the stories and decides to take Ork with him on a search for the fabled monsters when he's captured by one. Ork returns to get help and Sheera sets out to save her brother only to be captured herself.

Li'l Rok is trapped on a ledge by a giant dinosaur. Tor slips away, turns into Mightor and heads off to try and save his friend. He throws the dinosaur into the swamp only to discover that Li'l Rok has disappeared. Searching, Mightor find a nearby village where the residents have been enslaved by a group of humanoid insect creatures.

Tor is teaching Li'l Rok that to survive in the jungle, you must always be alert. They hear a signal call of the Tree Pygmies and prepare to run when Tor is captured and loses his club. Without it, he will not be able to turn into Mightor. Li'l Rok returns to the village to get help from Ork and Tog.

The Vulture Men have created a Great Stone Vulture in which they plan to entomb Mightor so it will gain his great powers. The villagers see the Vulture Men coming and Tor turns into Mightor to fight them off. They capture Li'l Rok and demand that Mightor surrender. Mightor agrees and is sealed in the Great Stone Vulture.

Tor, Sheera, Li'l Rok and their pets get trapped in a cave during a storm. Looking for another way out, they find themselves in the Valley of the Volcanoes where Charr and the Fire People live. The Fire People see the intruders and begin an attack. Tor finds himself trapped in a deep pit while the others are captured.

The Stone Men enter the village in their giant stone dragon looking for slaves and capture Sheera. When Tor sees that Sheera is captured, he offers himself as a slave in exchange for her release. The Stone Men go back on their word and keep them both as slaves. Tor is now without his club and must find some way to get it if he is to save them both.

Sheera and Li'l Rok get into a race with Tor while traveling on their rafts down a river. Tor gets caught up on some rocks and loses sight of his friends who find themselves shooting through rapids and landing on Vampire Island. Tor realizes that his friends are lost and turns himself into Mightor to attempt a rescue.

Chief Pondo and all of the men (except for Tor) go on a hunting trip. While they are away, the Cavebear Warriors come to the village and capture Sheera and Li'l Rok. Tor sees their tracks and turns himself into Mightor so he can attempt a rescue.

The Ice Creatures plan to move their glacier into the lowlands and take over the village and make Mightor their slave. They have a group of wooly mammoths push the glacier and ride it down the mountain and into the village. The villagers see the glacier approaching so Tor moves into action and turns himself into Mightor and the battle is on.

Tor is kidnapped by the Gill Men who bring him to the Serpent Queen. She wants to use him as bait to get revenge on Mightor. Li'l Rok, who witnessed the kidnapping, takes Tor's club and flies off with Ork to deliver it to Tor so he can battle the Queen's Serpent of the Pool.

Li'l Rok and a group of his friends decide to go rafting down a river to the Black Gorge. Sheera and Tor see the kids and know that it's too dangerous. Sheera takes off after the kids in a canoe while Tor turns himself into Mightor and heads out on a rescue mission. They run into one dangerous situation after another.

Li'l Rok is off by himself exploring when he comes across the Forbidden Temple of the Scorpion and is captured by the Scorpion Men. Sheera and Tor start to search for him when he hasn't returned by dark. Sheera is captured next, but Tor hears Bollo's call and turns himself into Mightor so he can attempt a rescue.

Numo and his Sea Slavers capture the women from the village as they are repairing the village fishing nets. The men discover that the women are missing and see the tracks left by Numo and his men. Tor takes quick action and turns himself into Mightor in an effort to follow the ships and rescue the women.

Tor and Sheera warn Li'l Rok of an approaching Terrible Beaked Bird. Li'l Rok discovers the nest of the creature and decides to retrieve the egg so he will be famous in his village. Sheera and Tor see him in the nest and know he will need help.

Li'l Rok, Sheera, and Tina are trying to catch butterflies and chase one into a nearby cave. When they come out the other side, they discover a strange world of man-eating plants. Luckily, Tor was following them in case they needed help, however, he loses his club and is captured with the others.

The Witchmen set out to find a queen for their ruler. They head to the village and find Sheera and Tor building a fire. They burn a bowl of "leaves of sleep" which incapacitates them both and they kidnap Sheera. Tor deducts that the Witchmen took her so he turns into Mightor and heads off in a rescue attempt.

The Vulture Men are headed for the village to get revenge on Mightor. They arrive and begin dropping boulders from their pterodactyls. Tor turns himself into Mightor and begins chasing them away which is exactly what the Vulture Men wanted. They had sent the winged monsters as decoys so they could attack the village when Mightor left.

The Mountain Monster Tribe's chief has decided that it is time he names his replacement. Gorg and Brog both make claims on the position so the chief proposes a challenge. Whichever of them is able to defeat Mightor will be the next chief.

The Storm King summons extra power from a lightning storm and now claims to have powers greater than Mightor. He appears at the village demanding to see Mightor. Pondo tells him that Mightor is not there and asks him to leave the village in peace. When the Storm King responds by putting Pondo in a deep sleep, Tor uses this distraction to turn into Mightor.

Li'l Rok and Ork find themselves lost in Hidden Valley. When Rok is seen by the villagers he's mistaken for their Great Horned god. As their proclaimed "true Champion," Li'l Rok accepts the offer to become their leader and defend the village against the Great White Terror, a creature who's more than Rok can handle.

Li'l Rok and Ork are fishing when they run into a boy named Norg of the Hill People. Norg is from a neighboring village and is looking for Mightor because Kragor and his Cavern Creatures have attacked his village. Li'l Rok tells Norg that he is Mightor and the two set off to run Kragor out of his village. Tor overhears, turns himself into Mightor, and is off to do battle with Kragor again.

Li'l Rok and Ork are trying to become the first from the village to capture a dinosaur from Dinosaur Island. He's able to snare one in a trap ,but the dinosaur proves to be too strong and makes an easy escape. Sheera and Tor find a note from Li'l Rok explaining where he has gone. Tor turns into Mightor and heads off to Dinosaur Island to help.

Tor and Li'l Rok fly to the village of the Valley People to surprise Sheera and discover the village is deserted. They begin investigating and Tor suddenly disappears, leaving his club behind. They discover that Rogg and the Stone Men have kidnapped their friends and plans to use them as slaves to build a stone Dinosaur of War.

Li'l Rok and Ork get lost during a storm and are captured by a group of strange insect men. Li'l Rok manages to escape by starting a fire as a distraction. Tor sees the smoke, realizes that Li'l Rok might be in trouble, and turns into Mightor to investigate.