Shadow is the "Ultimate Lifeform," created aboard the Space Colony ARK over fifty years ago by Professor Gerald Robotnik. He is the final result of Project Shadow, a government experiment that was only completed by infusing Shadow with the DNA of the alien Black Doom. After his birth, Shadow befriended Gerald's granddaughter, Maria Robotnik. However, the Guardian Units of Nations (G.U.N.) deemed the project a threat and raided the ARK, resulting in the captures of Shadow and Gerald, and the death of Maria. Driven to madness, Gerald altered Shadow's memories to one day seek revenge. Shadow remained in stasis for decades until he was freed by Gerald's grandson, Dr. Eggman. Fueled by vengeance, Shadow fought Sonic and friends until his true memories of Maria returned, inspiring him to save the world from Gerald's doomsday plot. However, Shadow fell to Earth and lost his memories in the process. Shadow would only learn the truth of his existence once he faced the Black Arms invasion of Earth. He has fought for Maria's wish of peace ever since, acting as a dark hero who protects the Earth and its inhabitants.

Ow the edge!