Sonic the Hedgehog protagonist Sonic the Hedgehog, a blue hedgehog able to run at supersonic speeds, and recurring villain Dr. Eggman, an evil scientist whose ambition is to conquer the world. Among Sonic's many allies, the most well-known include: Miles "Tails" Prower, a twin-tailed, highly intelligent yellow fox who is Sonic's sidekick and best friend; Amy Rose, a pink hedgehog who is Sonic's self-proclaimed girlfriend and a hero in her own right; Knuckles the Echidna, a coolheaded red echidna who is the guardian of the Master Emerald; Shadow the Hedgehog, an anti-heroic doppelgänger of Sonic with a dark past; and Metal Sonic, a
Sonic the Hedgehog (character) Sonic's first appearance in video games was in the 1991 arcade racing game "Rad Mobile", as an air freshener in one of the cars. Sonic's first major appearance was in the platform game "Sonic the Hedgehog" for the Sega Mega Drive/Genesis, which also introduced his nemesis Dr. Robotnik. His two-tailed fox friend Tails joined him in the game's 1992 sequel, "Sonic the Hedgehog 2". "Sonic CD", released in 1993, introduced Sonic's self-appointed girlfriend Amy Rose and recurring robotic doppelgänger Metal Sonic as Sonic traveled through time to ensure a good future for the world. "Sonic 3" and its direct sequel