Metal Sonic (Another Time, Another Place)

Metal Sonic is a robot duplicate of Sonic the Hedgehog, created by Doctor Eggman in an alternate reality.

Helping to Conquer Little Planet
Metal Sonic first assisted Doctor Eggman in his attempt to conquer the Little Planet, which involved the kidnapping of Amy Rose. This culminated in a race against his organic counterpart, Sonic, in which he was heavily damaged, thought to have been destroyed. (SSSM: #3)

Revival
Some time later, Eggman would return to the Little Planet during it's annuel passing over Never Lake, where he would retrieve and revive a still heavily damaged Metal Sonic... (SSSM: #3)

Olympic Trials
During the Olympic Games, Doctor Eggman captures all of Sonic's friends in several traps, disallowing them to compete in the events. As a substitue, Metal Sonic is made to challenge Sonic in all of the events, leaving Sonic extremely worn out, with one more event to go. However, after harnessing the power of the Olympic Spirit, Sonic defeats Metal Sonic in the 100 metre hurdle and frees his friends. (StH: #242)