Eggman Nega

Eggman Nega, also known as Dr. Nega, is a recurring villain from the Sonic the Hedgehog series. He comes from a different dimension that is actually the future and is the direct descendant of Dr. Eggman. Blaze the Cat, Silver the Hedgehog, Shadow the Hedgehog, and Sonic the Hedgehog are his main foes.

Mario & Sonic at the Olympic Winter Games
Eggman Nega appears as a boss in the Festival Mode and the Adventure Tours. He must be faced in Ski Cross for the Wii version and Nordic Combined and Skeleton for the DS version.

Mario & Sonic at the 2012 London Olympic Games
Eggman Nega returns as a rival in this game of London Party Mode. The player must wait for him to show up as a person to talk to. He does appear randomly. He is faced only in the Fencing and later Dream Fencing events. The player must beat Eggman Nega to win.