Waddlewing

Waddlewings are enemies that debuted in New Super Mario Bros. U. They are orange flying squirrel-like creatures with brown hands and feet, beady eyes, a red nose and a mouth with two incisor teeth. They also have orange membranes attached to their hands and feet and a cream-colored hindhead, ears and belly.

New Super Mario Bros. U / New Super Mario Bros. U Deluxe
Waddlewings are rather common enemies, mainly found in Acorn Plains and sky levels. Most of the time, Waddlewings glide from side to side. When they land, they will walk slowly and try to walk off a ledge to glide in that direction. If they bump into a wall or tree while gliding, they will cling to it for a second and then glide the opposite direction. Waddlewings can also carry Super Acorns and drop them if they are defeated. They behave like the Super Koopas from Super Mario World, but instead of obtaining equilibrium in flight, they will always glide diagonally. Additionally, if they are in the middle of gliding whenever the "bah" plays during the stage music, Waddlewings will perform a front flip.

New Super Luigi U
Waddlewings return in New Super Luigi U, behaving the exact same way as they did in New Super Mario Bros. U.

Mario Party: Island Tour
Waddlewings make a cameo in the minigames Starring Artist and Match Faker, from Mario Party: Island Tour.

Mario Party 10
Waddlewings reappear in Mario Party 10. They appear in the minigame Goomba Gallop, where they fly across the screen in an attempt to briefly obscure the players' view, as well as in the minigame Mega Goomba's Ladder Leap, where contact with one deducts one point. They also appear as selectable enemies in Meanie Match.

Mario Kart 8 / Mario Kart 8 Deluxe
While Waddlewings themselves don't appear in Mario Kart 8 or Mario Kart 8 Deluxe, a glider based on them called the Waddle Wing does.

Dr. Mario World
In Dr. Mario World, Waddlewings appear in World 25 after an area is cleared.

Super Mario-kun
A Waddlewing appears in volume 46 of Super Mario-kun. In the New Super Mario Bros. U arc, he accuses Mario and the gang for destroying his home by falling into the acorn tree.