The eclectic roster of crossover game Nickelodeon Kart Racers 2: Grand Prix includes characters from many eras of children's television. There are characters from the early 1990s with Ren & Stimpy, to the present day in 2020 with whoever JoJo Siwa is, making for a quirky lineup of competitors. You start off with 16 characters; add 14 unlockable characters to end up with a grand total of 30 Nickelodeon stars. Here's the complete roster and how to unlock everyone. Default characters All of these racers are unlocked from the beginning; the starting roster comprises of the most familiar mascots from Nickelodeon's library. SpongeBob (SpongeBob SquarePants)Patrick (SpongeBob SquarePants)Sandy (SpongeBob SquarePants)Leo\/Leonardo (Teenage Mutant Ninja Turtles (2012))Raph\/Raphael (Teenage Mutant Ninja Turtles (2012))Donnie\/Donatello (Teenage Mutant Ninja Turtles (2012))Mikey\/Michelangelo (Teenage Mutant Ninja Turtles (2012))Lincoln (The Loud House)Lucy (The Loud House)Tommy (Rugrats)Chuckie (Rugrats)Arnold (Hey Arnold!)Helga (Hey Arnold!)Rocko (Rocko's Modern Life)Zim (Invader Zim)Aang (Avatar: The Last Airbender) Unlock through Grand Prix There are eight cups to race through in Nickelodeon Kart Racers 2: Hairball Cup, Football Cup, Diapee Cup, Conglom-O Cup, Neptune Cup, ARGGH! Cup, DREAM Cup, and Super Slime Cup. Finish each one of these in overall first place on any difficulty to unlock one of the below characters. CatDog (CatDog)Gerald (Hey Arnold!)Angelica (Rugrats)Squidward (SpongeBob SquarePants)JoJo SiwaRen (The Ren & Stimpy Show)Clyde (The Loud House)Heffer (Rocko's Modern Life) Unlock through Challenges There are six sets of Challenges in Nickelodeon Kart Racers 2, each with six Challenges and a boss battle serving as a seventh Challenge. Complete three Challenges to unlock the boss battle, and defeat one of the below characters in a race to unlock them as a playable character. Danny Phantom (Danny Phantom)Stimpy (The Ren & Stimpy Show)Korra (The Legend of Korra)GIR (Invader Zim)Reptar (Rugrats)Shredder (Teenage Mutant Ninja Turtles (2012)) A couple of these boss battles have gimmicks. GIR's boss battle has you racing against multiple annoying GIRs. Reptar's boss battle has Tommy and Chuckie as wingmen. And the final boss battle with Shredder is significantly difficult, with his top speed and his constant throwing of obstacles at you.