Just like the need for a villian, a hero needs a sidekick. Sonic was luckly to receive the company of young Miles Prower, or Tails as he has two tails. Unique, smart, and dedicated, Tails would prove to be a valuable ally. Sonic has grown to consider the young fox as his kid brother.
Tails made his debut in Sonic the Hedgehog 2 for the Sega Genesis. It has always been Sonic Team's nature to add a new character each game. With others making fun of his two tails, Sonic stood up for him. He has followed the blue dude ever since.
Tails is smart, having a vast knowledge of technology. With his two tails, he can fly for a short time using them as a propeller. Sometimes I wonder if this was inspiration for Rayman's hair?
Young Miles has become popular with female fans of Sonic. I don't see why, but whatever makes their nipples hard I guess! XD