An immortal hedgehog made by Genarld Robotnik (Eggman). He is mostly black and red. When he first saw sonic he thought he was coping him. The First game he was in was Sonic Adventure 2. At the end he is suppoused to have his "Death Scene." Rouge The Bat is one of Shadow's friends (in her mind).
With the Heros
In Sonic Heros, Rouge The Bat finds Shadow in the deepest pit of Eggman's lair. When she finds him E-123 Omega trys to destroy him because he thinks he is Eggman's inventions. By then his memory is gone and he has no idea of Rouge (but helps her anyway), G.U.N., or Dr. Eggman, and etc. And he finds MANY MANY MANY andriods of him an he can't figure out if he is an andriod or not.
The Future and Beyond
In one of the games Shadow goes to the future and finds out he's the reason that the human race is failling (i think).
In Sonic Heros: Shadow finds out (near the end) that he is the real Shadow because Eggman said that he sent an andriod to save him so he found out he was the real Shadow.