Medusa and her group Crystal, Gorgon and Karnak, live in a beautiful city far away from civilisation. They plot to take over the whole world and make the human race their slaves. They call themselves the inhumans because of their unnatural powers: Medusa can control her hair, Crystal can control the weather, Gorgon can control the earth and Karnak is super strong.
When the Fantastic Four are travelling over the mountain, Medusa uses some things she placed to force them out of the sky. The Thing appears to be attracted to her. She tries to get them on her side, but when they refuse, she traps them in her underground dungeon.
She sees The Thing break out of his cell alone and she decides to control him.Medusa brainwashes him and then seduces him, pretending to be in awe of his great strength. She gets The Thing to attack the robot, pretending he wants to hurt her.
However, her spell is broken and together Invisible girl and her stretchy ally decide to escape the city. However, they are plagued by Gorgon and Karnak, who they swiftly defeat. When theyfind the Thing and The Robot, Crystal (revealed to be Medusa’s sister) uses a storm to ground them, which Medusa approves of.
Medusa, the Inhumans and her guards surround the Fantastic Four; she tells them to join her or die! However, the group defeat the Inhumans by cunning, they show them footage of what life is like in civilisation. Horrified, most of the Inhumans decide to leave civilisation alone; an angry Medusa briefly tries to get them to change their mind but fails. Furious, she swears vengeance before flying off, defeated.
Medusa reappears in the episode ‘The Frightful Four.’ She is called by the Sizard, along with The Trapster and The Sandman. She is the first, along with the wizard to be shown.
Medusa and the rest go to the city where The wizard uses his powers to steal pieces of jewellery, placing them in Medusa’s hair. When they are confronted by Elastic Man and Invisible Girl, Medusa faces off against Invisible Girl. She begins by shooting pieces of jewellery at the heroine, but she dodges and creates a shield. Medusa and Wizard both fail to impenetrate the shield, so they leave.
Later, the WIzard uses his magic to temporarily turn the team against each other; while they are squabbling Medusa uses her hair to abduct Herbie, the robot.
When The Fantastic Four go to the Wizard’s mansion, they are confronted by the seeming Frightful Four. They anger the Thing and he beats them up, including Medusa, but it is revealed that they are robots! The Frightful Four send traps intended to kill The Fantastic Four But they all escape.
The Four find the rogues in the cellar, but The Wizard stuns them. The villains suddenly disband and begin fighting with one another, while Herbie helps the heroes escape. Because of their powers, the mansion explodes and the rogues die, including the sultry bad girl Medusa.