He was created as part of 'Project Shadow' by Professor Gerald Robotnik, the grandfather of Dr. Shadow is a dark, short-tempered, and intimidating character on Mobius who most people try to avoid. In battle, Shadow is ruthless and attacks his foes with much aggression, wanting to end the fight as quickly as possible. He wants to quickly acquire the Chaos Emeralds and destroy Metallix without any interruptions, and is quick to be irritated should anyone (or anything) impede him of his progress. Shadow is one for focusing on the task at hand and cares little for anything else. He also takes pride in his power as the 'Ultimate Lifeform.' Despite clashing with Sonic in terms of personality, he does share his smug attitude, overconfidence, and tendency to mock his opponents. Although silent most of the time, Shadow is usually blunt and is never afraid to speak his mind. He is described to be that of a lone-wolf, preferring to be by himself and handling things his way. Shadow is famous, or rather infamous, for his cold and intimidating nature. On each of his wrists and ankles, he wears a single gold ring. He wears white gloves with black cuffs and red tongues, and Air Shoes which, like his gloves, have black cuffs and red tongues. He has six quills on his head, four of which curve upwards and two that curve downwards, two spines on his back, and a small tail. He has red eyes, a patch of white fur on his chest, and his muzzle is tan. Shadow is a hedgehog with black spines and red stripes on his quills, around the edges of his eyes, and on his arms and legs.

Are sonic and shadow brothers