Nine

Nine is an alternate version of Tails in which he never met Sonic and was bullied, so he created six metal tails on his back. He is cold towards others except Sonic, as he is the only one who called him a friend and treated him normally. He doesn't trust many, doesn't communicate with anyone, and is self-reliant. He is quite intelligent and knowledgeable about technology.

He lives in a gloomy world where there are only rocks, and his base is made of a paradox prism. He has guards who are like Sonic's friends, but made of metal; he calls them "grim."