Hydron and Flipshot travel in the Starship searching for the legendary hero He-Man, but Skeletor tricks them into believing he is He-Man and asks them to transfer the power of Castle Grayskull into their starship. Prince Adam arrives and becomes He-Man inside the ship, finishing the misunderstanding, but the power cannot be returned to Grayskull, since the powers of the past and the future have joined (as evidenced by He-Man's changed looks). Since the starship was named after the legendary planet Eternia, He-Man must now invoke the power by shouting "By the power of Eternia!"
It appears in The New Adventures of He-Man.
The Starship Eternia toy could be re-shaped in a variety of forms, like a base or an observation center.