Sonic

Sonic is a Supersonic Hedgehog, and is one of the main heroes of SMBZ

Canon Biography
In the games, this famous hedgehog has been Sega's official mascot for 18 years. Sonic is a blue hedgehog who runs at the speed of sound. He is a very easy going hedgehog, who frequently runs wherever he pleases. He has battled against the evil Dr. Eggman for many years. That is until Metal Sonic came, Sonic battled against him countless times, which fueled the robotic tyrant's determination to defeat his anthropomorphic counterpart. His friends were murdered by Mecha Sonic, and now Sonic along with Shadow join the Mario Bros to put an end to the mechanical demon's evil schemes and prevent the destruction of the Mushroom Kingdom as it happened in Mobius, Sonic's homeworld

Fanon Appearences
In EdGeorgenCody's Episode 9: Revenge of the Ninja, Sonic, Yoshi and Luigi are freed from their stone state by Shadow, and all four help Mario, In the Koopaling Battle, Sonic battles Ludwig and Iggy, taking care of both easily. He is frozen in time, Along with Shadow and Mario, by King Boo at the end of the episode, Which in he also accidently revives The Koopa Bros., Who are now the Dry Bros.