Scourge the Hedgehog is an evil alternate reality version of Sonic the Hedgehog. Scourge first appears after the villains escape from prison, and tells them about the Dreamcast Era, setting the stage for the restoration of the White Space. Scourge reappears after Modern Sonic, Dreamcast Sonic, and Classic Sonic restore the Dreamcast Era, but this time with Fleetway Super Sonic, another evil Sonic. Scourge and Fleetway Super Sonic then proceed to attack the heroes, but are defeated. Scourge returns in Season 24, where he is seen working with Fleetway Super Sonic once again so they can get all seven of the Chaos Emeralds, which were scattered by Infinity Helios to prevent Metal Sonic from getting them. Scourge, Fleetway Super Sonic, and Metal Sonic later battle against Sonic in the Doom Dimension. However, Scourge is quickly defeated, even after transforming into Super Scourge. Scourge later helps the Heroes of Legend and the Battle Brawlers escape from the Doom Dimension, but stays behind with Metal Sonic to find Fleetway Super Sonic. Scourge and Metal Sonic later escape the Doom Dimension after an unsuccessful search and sneak into the Vestal Destroyer. At the start of Season 25, Scourge is betrayed by Metal Sonic, who roboticizes him and transforms him into Metal Scourge. Scourge is later deroboticized by Dr. Eggman. In Season 32, following Metal Sonic's reformation, Scourge takes it upon himself to bring Metal Sonic back to the side of evil, to the point of restoring Tikal's memories despite Tikal reverting to her psychopathic personality as a result. During the Angel Island conflict, Scourge tricks Metal Sonic into entering the conflict so he could reprogram him. Scourge also prevents Rosalina from recovering her sanity by his unforgivable act of shooting Princess Peach.
Unlike the prime Sonic, Scourge has green fur and wears a black jacket with a flame pattern as well as sunglasses and different shoes.
Scourge is selfish and power-hungry, unlike Sonic. In Season 32, Scourge is shown to be a cruel and uncaring individual that will do whatever it takes to accomplish his goals. This is evident when Scourge mercilessly shot Princess Peach in the back with no remorse (although his original target was Rosalina), insulting Peach for her stupidity.
- With the exception of his first battle and his fight with the Heroes of Legend on Volcano Island, Scourge's battles usually occured in the Doom Dimension.
- Since the recreation of the Smash World, it seems that Scourge has become the leader of the League of Villains.
- Unlike Sonic, Scourge is frequently seen carrying a shotgun.