The Sonic the Hedgehog video game franchise began in 1991 with the game Sonic the Hedgehog for the Sega Genesis, which pitted a blue anthropomorphic hedgehog named Sonic against a rotund male human villain named Doctor Eggman. The sequel, Sonic 2, gave Sonic a fox friend named Tails. Sonic CD introduced Amy Rose, a female hedgehog with a persistent crush on Sonic. Sonic 3 introduced Knuckles the Echidna, Sonic's rival and, later, friend. All five of these have remained major characters and appeared in dozens of games.
