Sonic Underground

Sonic Underground is an animated series that follows the adventures of Sonic the Hedgehog, and his siblings Sonia (his sister) and Manic (his brother). Sonia is a pink hedgehog, who wears a purple dress. Manic is a green hedgehog who is similar to Sonic in apperence beside the fact that he wears a red vest and his first two spines are replaced by spiky hair. It bared little continuity with the often convoluted Sonic universe - including previous animated series, and Sonic comics and games - and, apart from Sonic and Robotnik, few established characters. Despite having an original storyline & approach, it's considered by most to be the worst of the three American Sonic cartoons.

Trivia

• Is the first American series to feature Knuckles. It is also the only show to feature a relative of Knuckles': his great-grandfather Athair, voiced by Sean Connery. Something of a casting coup for the program, this was the first television guest appearance Connery had made playing a character (as opposed to playing himself) since 1956.
• The Archie Sonic comics consider Sonic Underground as alternate universe version of Sonic, and has made one appearance in the series, in Sonic Super Special #10.