Shadow was created as the ' Ultimate Life Form' (究極生命体, Kyūkyoku Seimeitai) by Professor Gerald, using the DNA of Black Doom, and is the end result of Project Shadow. He is an anthropomorphic black hedgehog/ Black Arm hybrid, a dark doppelgänger, and the arch-rival of Sonic the Hedgehog.
Shadow the Hedgehog (シャドウ・ザ・ヘッジホッグ, Shadō za Hejjihoggu) is a fictional character and deuteragonist from the Sonic Pokémon series.