Like Captain Falcon of F-Zero fame, Sonic too has an army of rivals. Knuckles is considered to be a friendly rival. Sonic's darkest and most powerful yet is Shadow the Hedgehog.

Shadow first appeared in Sonic Adventure 2 for the Dreamcast and Gamecube. Created by Eggman's grandfather Prof. Gerald Robotnik, Shadow was the Ultimate Lifeform. After 50 years of suspended animation, Shadow was released by Eggman and was given the chance to get revenge on mankind. In the end, he would remember the words of his friend Maria and save Earth from destruction.

Shadow has black fur, with streaks of red all over his body. A tuft of white hair lay on his chest. His powers include speed rivaling Sonic and chaos powers. When enraged, Shadow can use chaos blast destroying everything in site. In other cases, he can use chaos control to teleport.

In 2005, Sega gave the dark hedgehog his own game. Giving a darker story and more insite into Shadow's past, the game also introduced a gun mechanic. This would differentiate his play style from Sonic's.

Sonic isn't the only character to be cloned. Shadow has been cloned on several occassion. Eggman created androids of the hedgehog and Mephiles even stole his image.

What is the future for Shadow? He has let go of his past and has become a defender of Earth along with Sonic and friends. Will he continue this streak? Will his finally bang Amy? Only time will tell.