Satellite galaxies, also called dwarf galaxies, were small galaxies that orbited larger galaxies. They contained many stars, but not as many as a larger galaxy.
Mutter's Spiral had a satellite galaxy called the Sculptor Dwarf galaxy or Galaxy Seven. (PROSE: The Eyeless) It also had the two Magellanic Clouds, called the Larger Magellanic Cloud and Smaller Magellanic Cloud. (AUDIO: The Last Voyage)