Masters of the Universe is a sword and planet-themed media franchise created by Mattel. The main premise revolves around the conflict between He-Man and Skeletor on the planet Eternia, with a vast lineup of supporting characters in a hybrid setting of medieval sword and sorcery, and sci-fi technology. A follow-up series, She-Ra: Princess of Power revolves around He-Man's sister She-Ra and her rebellion against The Horde on the planet Etheria. Since its initial launch, the franchise has spawned a variety of products, including multiple lines of action figures, six animated television series, several comic series, video games, books and magazines, a daily newspaper comic strip, and two feature films.

He-Man is a superhero and the protagonist of the sword and planet Masters of the Universe franchise, which includes a toy line, several animated television series, comic books, and a feature film. He-Man is characterized by his superhuman strength and in most variations, is the alter ego of Prince Adam. He-Man and his friends attempt to defend the secrets of Castle Grayskull, the planet Eternia, and the rest of the universe from the evil forces of his archenemy Skeletor. He-Man is also the twin brother of She-Ra.