Sonic Underground - Season 1 Episode 16 Friend or Foe?
Overview: 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.