Synopsis

Sonic, Sonia, and Manic are the children of Queen Aleena Hedgehog, the rightful ruler of Mobius, and are pursued relentlessly by Doctor Robotnik and his bumbling bounty hunters sidekicks, Sleet and Dingo. As infants, the siblings were separated and placed in hiding to fulfill a prophecy made by the Oracle of Delphius that the triplets would grow up to find their estranged mother, overthrow… Robotnik, and take their places once more as Mobius' rightful rulers.

The show bible was written as early as March 1997.

DIC used cattle calls to generate episode plots.

According to Mike Piccirillo, when he was writing songs for the show, there were no storyboards done yet, so he could only work off of the scripts, which often said what moral or lesson the song should be about in each episode.

While it was once believed that 65 episodes were made of which only 40 aired, Ben Hurst, a main writer from Sonic the Hedgehog (dubbed SatAM by fans), who was also involved in Sonic Undergrounds production, stated in a chat at the Sonic Amateur Games Expo 2008 that only 40 were planned to be produced from the beginning.

Sonic Underground started production in early 1997, around the same time the development of both the Dreamcast and Sonic Adventure had started.