Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ Sonikku za Hejjihoggu) is a video game franchise created and owned 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, published in 1991, was conceived by Sega's Sonic Team division after Sega requested a mascot character; the title was a success and spawned sequels, and transformed Sega into a leading video game company during the 16-bit era in the early to mid-1990s.
While the first games in the series were side-scrolling platform games, later games expanded the series into various other genre and sub-series, notable the Mario & Sonic at the Olympic Games and Sonic Boom. As of 2015, the series had sold approximately 87.82 million physical copies of games, and over 335 million units when combining including packaged game software with mobile phone downloads. In addition to a long list of games released through 2016, two future games, Sonic Mania and Sonic Forces are scheduled for release in 2017. Outside of video games, the series has also been spun out into other media, including cartoons, anime, and a long-running comic book series.