Suggestions by @willsheffield

Ninji

as New Racers in Mario Kart 9

Dr. Crygor

as New Racers in Mario Kart 9

Ashley (Wario Ware)

as New Racers in Mario Kart 9

Viruses

as New Racers in Mario Kart 9

Mallow

as New Racers in Mario Kart 9

Pikmin

as New Racers in Mario Kart 9

Mona (WarioWare)

as New Racers in Mario Kart 9

Nabbit

as Returning Racers from other titles in Mario Kart 9

Monty Mole

as Returning Racers from other titles in Mario Kart 9

Professor E. Gadd

as New Racers in Mario Kart 9

Prince Florian

as New Racers in Mario Kart 9

Cappy

as New Racers in Mario Kart 9

Dixie Kong

as Returning Racers from other titles in Mario Kart 9

Prince Bowser Koopa Jr.

as Returning Racers from 8 in Mario Kart 9

Shy Guy

as Returning Racers from 8 in Mario Kart 9

Red Toad

as Returning Racers from 8 in Mario Kart 9

Petey Piranha

as Returning Racers from 8 in Mario Kart 9

Toadette

as Returning Racers from 8 in Mario Kart 9

Koopa Troopa

as Returning Racers from 8 in Mario Kart 9

Kamek (Magikoopa)

as Returning Racers from 8 in Mario Kart 9