Mecha Sonic

Mecha Sonic is the main villain of the series

Canon Biography
Mecha Sonic (originally known as Metal Sonic) is a robot created by Dr. Eggman for the sole purpose of destroying Sonic. He serves as the primary antagonist for the first saga of Super Mario Bros. Z. In his original appearances (Episodes 1 - 3), Mecha Sonic was given voice clips of the Ninja Robots Cyrax, etc, from Midway's Mortal Kombat 3. However, starting with Episode 6, he is given voice clips of Final Form Cooler from the "Dragon Ball Z: Budokai Tenkaichi" series of games (with the exception of his saying "Chaos Blast").

Fanon Appearences
In EdGeorgenCody's SMBZ Episode 9, Mecha Sonic Starngely, does not appear.