knuckles is a red Echidna warrior with super strength and he's also the holder of the master emerald (magic green emerald the size of someone's hand)

sonic is a blue hedgehog with super speed

tails is a yellow fox with 2 tails (can fly with the tails)

tom and maddie are married (humans) and they take care of knuckles, sonic and tails

ozzie (tom and maddie's dog) is a golden retriever

Rachel (maddie's sister) and Randall (rachel's husband), jojo is their daughter