Shadow is Spain's favourite Sonic character. He's 3' 3'' tall and weighs 77 lbs and was built by Professor Gerald Robotnik, Eggman's grandfather. He was created as the ultimate life form. He first appeared in Sonic Adventure 2 (Dreamcast, 2001) where Sonic saw him walking on a robot. His own videogame is Shadow the Hedgehog (PS2, Xbox 2005) and I also remember a few episodes of Sonic X (Europe/Japan/Latin America 2003-2004, USA 2003-? 2007) where I saw Shadow in a few parts of it, and also a TV commercial of his game. Shadow doesn't remember anything.
(Photo: SEGA of America Inc.)
In the real world he was created by Yuji Uekawa.