There are a few different answers depending on if you are talking about the real world or one of the Cartoons. Miles "Tails" Prower's character designer wanted the name "Tails" and snuck the name in as a nickname. In the cartoons, Sonic saw that "Tails" could fly and the nickname stuck.
It was always his nickname.
No, he doesn't plus Miles "Tails" Prower is only 8 years old.
Miles tails prower is a fox from the sonic the hedgehog videogames.
Tails is a boy. His full name is Miles "Tails" Prower. Tails is just his nickname since he can fly with his two tails.
No. He told Sonic he did not like his name so Sonic gave him the nickname Tails.
Tails the Fox's real name is Miles Prower.
Miles Prower,A.K.A. 'Tails',Sonic gave him the Nickname 'Cuz Tails was Disliking of his real name.
Miles "Tails" Prower is not a girl, he is male, if he was a girl it would have been established.
marine
ELEPHANT!
miles prower (tails)
No