Metal Sonic

Metal Sonic is an evil robotic version of Sonic the Hedgehog from the  franchise, created by Dr. Eggman. As with Knuckles the Echidna and Shadow the Hedgehog, he is one of Sonic's rivals, and despite being a robotic copy of the original, he believes that he is the one that deserves to be the real Sonic.

Metal Sonic has appeared in crossover games with the Mario franchise, the first of them being Super Smash Bros. Brawl as a sticker. He later made a playable appearance in Mario & Sonic at the Olympic Winter Games.

While Metal Sonic was voiced in Sonic Heroes by, Sonic's voice actor at the time of the game's release, in the Mario & Sonic series, he uses computer-generated sound effects instead.

Super Smash Bros. Brawl
Metal Sonic makes a cameo appearance in Super Smash Bros. Brawl as a collectible Sticker.

Super Smash Bros. for Nintendo 3DS
Metal Sonic appears as a trophy in Super Smash Bros. for Nintendo 3DS.

Super Smash Bros. Ultimate
Metal Sonic makes an appearance as a Spirit in Super Smash Bros. Ultimate.

Mario & Sonic at the Olympic Winter Games
Metal Sonic's first playable appearance is in Mario & Sonic at the Olympic Winter Games. He is a Speed type character and is naturally good in all racing events. His special skill is the Air Boost.

In the Adventure Tour of the DS version, he tries to stalk Mario & Sonic in Sparkleton and challenges them to a Rocket Ski Jumping event. If they win, Metal Sonic will let them proceed.

There is an added detail in the DS version of the game, in which Metal Sonic's eyes turn blue if the player wins an event, is in the lead, or is playing certain events. This appears to be a reference to Sonic R, in which a similar effect happens to Metal Sonic when he is in the lead and/or wins.

Mario & Sonic at the London 2012 Olympic Games
Metal Sonic returns in Mario & Sonic at the London 2012 Olympic Games as a Speed type character.

Mario & Sonic at the Sochi 2014 Olympic Winter Games
Metal Sonic reappears in Mario & Sonic at the Sochi 2014 Olympic Winter Games as a Speed type character once again.

Mario & Sonic at the Rio 2016 Olympic Games
Metal Sonic is a playable character in Mario & Sonic at the Rio 2016 Olympic Games. He is once again a Speed type character.

Mario & Sonic at the Olympic Games Tokyo 2020
Metal Sonic reappears as a playable character in Mario & Sonic at the Olympic Games Tokyo 2020.

Official Profile
''Metal Sonic is new to the world of the Olympic Games. Modeled with extreme accuracy to Sonic by Dr. Eggman, Metal Sonic is one of our blue hero's earliest foes. At the Olympic Winter Games, Metal Sonic hopes to gain an advantage with his unique ability on the Wii and DS known as the Air Boost.''