Space Mice have lived on Arus even before the Castle of Lions was built. The Space Mice were Princess Allura's friend since her childhood. They often try to be helpful to the Princess and the Voltron Force. There are five Space Mice who live in the Castle. There is a large light blue mouse (named Suki in the English dub), a large pink mouse, two medium-sized light blue mice, and a much smaller light blue mouse.