Who is the gray Sonic?

Who is the gray Sonic? Silver the Hedgehog (シルバー・ザ・ヘッジホッグ, Shirubā za Hejjihoggu?) is a fictional character in the Sonic the Hedgehog series.

Silver the Hedgehog (シルバー・ザ・ヘッジホッグ, Shirubā za Hejjihoggu?) is a fictional character in the Sonic the Hedgehog series.