The information said here is non-canon as Super Smash Bros. Battle Beyond, Diddy Kong Racing Wii U, etc. isn't a real (canon) game and as of the fan information said about this character. For the canon information about this character read here
Rocket Knight Adventures
Rocket Knight (2010)
Sparkster is a fictional character and eponymous hero of the Rocket Knight series. He's an anthropomorphic opossum and is the leader of the Rocket Knights. Since his playable appearances in Super Smash Bros. Battle Beyond and Diddy Kong Racing Wii U, he was given DLC in Sonic & All-Stars Racing Transformed, Mario Kart 8, Donkey Kong Barrel Blast 2, and Super Mario Maker (as a amiibo costume) for his low popularity beside his series.