Sonic was originally a normal brown hedgehog, who burrowed his way into the underground laboratory of Dr. Ovi Kintobor, a scientist who wished to rid the planet Mobius of all evil through the use of powerful gems called the Chaos Emeralds. In addition, he helped Sonic increase his running speed using a special treadmill, until the hedgehog eventually broke the sound barrier with a sonic boom which turned him blue. However, an accident involving the unstable Chaos Emeralds and a rotten egg transformed Kintobor into the evil Dr Ivo Robotnik
