Wave the Swallow
From the Super Mario Wiki
Wave the Swallow (or simply Wave) is an eighteen-year-old swallow and the mechanic of the Babylon Rogues. She plays her most prominent roles in the Sonic Riders series.
Super Smash Bros. Brawl
Mario & Sonic series
While Wave makes no appearance in the games prior to the fifth installment, she has a Mii costume based on her in Mario & Sonic at the London 2012 Olympic Games and Mario & Sonic at the Sochi 2014 Olympic Winter Games.
She makes a playable appearance in Mario & Sonic at the Rio 2016 Olympic Games. This is her only physical appearance outside of the Sonic Riders series.
Super Smash Bros. Brawl sticker information
Crossover game appearances