Milky Way and The Galaxy Girls/YMMV


 * Ensemble Darkhorse: Pluto, at least among the girls whose dolls are available. She even has a fan-made theme.
 * Rule 50: Bronies, loving all things Lauren Faust, have made a few My Little Pony/Galaxy Girls crossovers. You can see a few in Lauren's Galaxy Girls fanart favorites section of her Deviant ART page.