Shadow the Hedgehog (シャドウ・ザ・ヘッジホッグ, Shadō za Hejjihoggu) is a character from the Sonic the Hedgehog series who, like Knuckles, has a bit of a rivalry with Sonic. He is known as the "Ultimate Life form." He has his own game that mainly features him, the self-titled Shadow the Hedgehog, which was released in 2005 for all three sixth-generation consoles (except the Sega Dreamcast, which was discontinued before Shadow the Hedgehog was planned). Since his debut, he consistently holds second place as the most popular character in the franchise, trailing the obvious Sonic. Unlike his heroic counterpart, Shadow is a much darker and developed character, willing to do whatever it takes to reach his goals. However, in the recent games, he has become a somewhat lighter, anti-hero character.
Shadow the Hedgehog first appeared in Sonic Adventure 2 as one of the main antagonists. He seemed to match Sonic in speed using his infamous skating technique to run. In his debut game, Shadow attempts to frame Sonic for crimes he did not commit and spends the rest of the adventure chasing him down as Sonic tries to stop The Final Hazard. Towards the end, he is presumed dead after an incident at the Space Colony ARK. At the beginning of Sonic Heroes, he is discovered in a stasis module in an abandoned factory and awoken by Rouge the Bat. Shadow then forms Team Dark with Rouge and E-123 Omega, who all strive to get revenge on Doctor Eggman for their own reasons. From then on, although he remains a strong rival to Sonic, he is sometimes forced to ally with him to take on a much greater threat.
Shadow appears as an unlockable Assist Trophy character in Super Smash Bros. Brawl. He uses his "Chaos Control" ability to slow down everyone except the summoner, similar to the effects of the Timeritem, though with a shorter duration. Shadow the Hedgehog is unlocked when Sonic is unlocked as a playable character. He also appears as a regular Trophy.
In Brawl, Shadow the Hedgehog is voiced by Jason Griffith in the English version of the game (who also voices Sonic), and Kouji Yusa in the Japanese version.
Shadow The Hedgehog is a black hedgehog who resembles Sonic. He was created by Dr. Eggman's grandfather, Gerald Robotnik, to be the ultimate life-form. Not only does he look like Sonic, but he has equal abilities. He has great skill with the space-time warping technique called Chaos Control. To reach his goals, he'll use any means necessary.