Rouge

Rouge the Bat is a character from the Sonic Series. The only connection she has to Mario is a possible appearance in Mario & Sonic at the Winter Olympic Games, where she is not confirmed as a character, but is made into an outfit for Miis to wear.

History
She has the ability to fly with her bat wings. In the sonic series, Rouge plays a somewhat big role. She is a crook who is fond of stealing the Chaos Emeralds along with Shadow the Hedgehog. She occasionally will help out Sonic and friends. She has shown to have a crush on Knuckles, however, it might be so she can steal Knuckles' Master Emerald.

Mario and Sonic at the Olympic Games
Rouge was supposed to appear in the game as a playable character alongside Donkey Kong, Silver the Hedgehog and Birdo. She was removed from the first game because her clothing design was inappropriate for younger players. She and Birdo are the only ones out of the 4 who have no sign of playable appearance in the series yet.