At some point prior to episode 7 Bowser met a scientist, 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.
Super Mario Bros. ZX
Mecha Mario appeared as an antagonist, he was responsible for beating Mario's friends including Luigi and Sonic, Mario gets mad and turns into Dark Mario and seeking his revenge against Mecha Mario.