Sonic Underground - Season 1 - Eps 16: Friend or Foe?
The Hedgehogs converge on the Floating Island, in their latest attempt to find their Mother. Sleet and Dingo also have an interest in this island that involves the Chaos Emerald, which is the island's life-force. But, before either party can achieve their goals, they have to get through Knuckles, the floating island's stern guardian.
About Sonic Underground

Title: Sonic Underground
First Air Date: 1999-08-30
Last Air Date: 1999-10-22
Status: Ended
Rating: 6.9/10 (from 145 votes)
Language: EN
Seasons: 2
Total Episodes: 40
Network: TF1 Syndication
Genres: Action & Adventure, Animation, Kids
Production Companies: Les Studios Tex SARL, DiC Entertainment, TF1
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.
Cast

Jaleel White
Sonic / Manic / Sonia (voice)

Garry Chalk
Dr. Robotnik (voice)

Maurice LaMarche
Sleet (voice)

Peter Wilds
Dingo (voice)

Gail Webster
Queen Aleena (voice)

Ian James Corlett
Cyrus (voice)

Sam Vincent
Sonic (singing voice)

Tyley Ross
Manic (singing voice)

Stevie Vallance
Sonia (singing voice)