According to official profiles, Shadow was created over 50 years ago by Prof. Gerald Robotnik as the Ultimate Life Form.[14][15] Shadow is sharp witted, seemingly always on the edge,[15] and is described as the dark incarnation or an Alter Ego look-a-like of Sonic.[16] Once he has set himself to a goal, he will do whatever it takes to accomplish it,[15] regardless of any danger.[17] After the trauma of the death of his only friend, Maria Robotnik, Shadow strives to fulfill his purpose and keep the promise he made to her,[15] despite his general loathing of mankind.[17]

However, Shadow shares a lot in common with Sonic.[17] Although Sonic's speed is described as "second to none," Shadow can skate at speeds fast enough to rival the speeds of Sonic's running.[18] He can also perform spin attacks common to Sonic,[14] which are a variation on the tendency for hedgehogs to roll into tight balls for protection. Additionally, with the power of a Chaos Emerald, Shadow can warp time and space with Chaos Control.[14][16][17] Shadow is also able to use a variety of other Chaos powers, such as "Chaos Spear" and "Chaos Blast".[17] Much like Sonic solely believes he is the fastest thing alive, Shadow truly considers himself the "ultimate life form", regardless if he's the real one or not.

By harnessing the power of the seven Chaos Emeralds, Shadow is able to use super transformation to transform into Super Shadow,[19] and is bestowed with the new abilities of flight and near invulnerability, like Super Sonic, and his normal abilities of speed and his Chaos powers are greatly enhanced. However, this does come at the cost of a time limit on the transformation. Although he is mostly a maverick, he also works with his team (Team Dark) and is mostly portrayed as rough and cold. He is not without positive emotions, though, and has shown these rare tendencies on a few occasions. Shadow has a very strong sense of justice, often going to extreme lengths to ensure such