Shadow

Shadow the Hedgehog (シャドウ・ザ・ヘッジホッグ Shadō za Hejjihoggu?) is a fictional character from the Sonic the Hedgehog series. He is an anthropomorphic hedgehog/Black Arm hybrid and the arch-rival of Sonic the Hedgehog. Shadow was created as the "Ultimate Life Form" (究極生命体Kyūkyoku Seimeitai?) by Gerald Robotnik, using the DNA of Black Doom, and is the end result of Project Shadow. His purpose was to provide ways to develop a cure for incurable deadly illnesses, more specifically for Gerald's granddaughter Maria Robotnik, but he was captured and put into stasis by the military when he was deemed as a threat to humanity.