Knuckles The Echidna is the third main character of the series. He is the red echidna with spiky gloves and long tail, his favorite food is fruit, especially Grapes. He is a proffesional fighter. His first appearance is on Sonic 3. And in the show, the first appearance is in "Unlike Sonic, I don't chuckle!" episode.
He can glide, climb on walls and punch.
His age is 18, because Sonic Generations was been released.
- Sonic The Hedgehog - the blue hedgehog known as the Fastest Thing Alive and Blue Wind
- Miles "Tails" Prower - the orange fox with 2 tails, he's a mechanic.
- Red Bird - the cardinal, appears on the very first level in Poached Eggs episode on Angry Birds.
- Black Bird - the bomb bird, has the ability to explode and destroy stone blocks that Pigs use for building a strong "Stone Fortress"
- Espio the Chameleon - the purple chameleon that has the ability to become invisible.
- Shadow the Hedgehog - the black hedgehog with red strippes on his spikes, legs and arms, he is known as the "Ultimate Life-Form", and he's Sonic's rival.
- Dr. Eggman - The evil genius trying to take over the world, but he needs emeralds. His name is known as Robotnik.
- E-102 "Gamma" - the robot with a gun on his arm, his first appearance is on Sonic Adventure.
- Rouge the bat - the bat, that loves to collect the diamonds and emeralds, she steals Knuckles' Master Emerald and he wants to take it back.
- Metal Sonic - the Sonic's robot clone created by Dr. Eggman.
- Chaos (green Knuckles)
- He is great at street fighting.
- Sonic calls Knuckles an "Knucklehead".
- He hates thieves who steal his Master Emerald.
- There's Knuckles' metal copy named "Metal Knuckles", created by Dr. Eggman.