Mecha Mario

Mecha Mario is a robotic double of Mario built by Bowser's "secret assistant." He has so far appeared only once, briefly in the beginning of episode 7. Mecha Mario's exact role in the series is currently unknown, but will be revealed hopefully soon.

Biography
At some point prior to episode 7 Bowser met a scientist, most likely Dr. Eggman (though this hasn't been officially confirmed yet), who informs Bowser of the Chaos Emeralds. Bowser commissions two secret weapons from the doctor: the Omega Doomship and Mecha Mario. When Bowser learns that Mario is searching for the Chaos Emeralds, he decides to invade the Mushroom Kingdom and kidnap Princess Peach while Mario and his friends are away. Bowser then goes to check on the progress of his new weapons: although the Omega Doomship's defense system hasn't yet been installed, Mecha Mario appears to be fully functional.