Wacky Races, a racing game based on the classic Hanna-Barbera cartoon, was a prototype title for the Sega Genesis, meaning it was never officially released to the public. While details about its gameplay are scarce, it almost certainly would have featured characters and vehicles from the show, competing in chaotic races.  The developer remains unknown but given its source material likely targeted fans of the cartoon.

Wacky Races (USA) (Proto)

Vixen 357 (Japan)