Sonic the Hedgehog is a video game franchise created and produced by Sega. The franchise centers on a series of speed-based platform games. The protagonist of the series is an anthropomorphic blue hedgehog named Sonic, whose peaceful life is often interrupted by the series' main antagonist, Doctor Eggman. Typically, Sonic—usually along with some of his friends, such as Tails, Amy, and Knuckles—must stop Eggman and foil any plans of world domination. The first game in the series, released in 1991, was conceived by Sega's Sonic Team division after Sega requested a mascot character. The title was a success, it spawned many sequels, and it transformed Sega into a leading video game company during the 16-bit era in the early to mid 1990s.