Friend or Foe?

"Friend or Foe?" is the eighteenth episode of the Sonic Underground television series. The episode was written by Kevin Donahue and first aired on January 18, 2000. It was included in the collection "Secrets of the Chaos Emerald".

The song performed in this episode is "Not Always What They Seem".

Plot
The band visit the Floating Island in search of their mother. There they meet Knuckles the Echidna, the island's guardian, who has been falsely told by Sleet and Dingo that the Sonic Underground is after the Chaos Emerald. Knuckles jumps to conclusions, and while he and Sonic the Hedgehog battle each other, Sleet and Dingo set their eyes on the Emerald.