Miles "Tails" Prower

Miles Prower (マイルス・パウアー, Mairusu Pauā), better known by his nickname Tails (テイルス, Teirusu), is Sonic's best friend and sidekick. He has appeared in nearly every game since Sonic the Hedgehog 2. His specialty is mechanics. He is a playable character in Super Smash Flash and Super Smash Flash 2.

Character description
Yasushi Yamaguchi, originally the main artist and zone designer for Sega's Sonic Team, designed Tails for an internal competition for a sidekick to Sonic the Hedgehog. The character was meant to hold a "deep admiration for Sonic." His entry won, but Sonic Team decided to change his character's name from "Miles" to "Tails." Yamaguchi ended up with a compromise. He sneaked the name "Miles" in as his legal name; "Tails" would be his nickname, ending up with the full name of Miles "Tails" Prower which is a pun of the phrase "miles per hour". When Tails was released on Sonic the Hedgehog 2 for the Game Gear, many people mistaken him for a female due to his opening pose, which shows him winking and showing his back.

The character debuted as Sonic's tag-along partner in the franchise's second game, Sonic the Hedgehog 2, and has remained an important player since. However the character's uniqueness wasn't established until Sonic the Hedgehog 3 when players were given the power to control his flying. Tails was redesigned (along with all of the other Sonic characters) by Yuji Uekawa for Sonic Adventure. His fur changed color to a slightly orange shade of yellow, and he gained visible sparkling blue irises. In the American Sonic comic book, along with the Adventures of Sonic the Hedgehog and Sonic the Hedgehog cartoons, he was originally brown, but the comic artists eventually decided to change this to match his in-game appearance.

Tails appears in "Sonic the Hedgehog: The Movie" (also known as "Sonic Anime" or "Sonic OVA"), along with Knuckles, Sonic, Metal Sonic and its creator, Robotnik (also known as Dr. Eggman, or just "Eggman" in Japan).

Within games and other media, Tails is portrayed as a very sweet-natured and humble fox; who, before he met Sonic, used to be picked on because of his two tails, which he has due to a birth defect. As a long time friend, he admires Sonic and dreams of being just like him. Though he lacks courage, he wants to prove he can be counted on. He loves mint candy, tinkering with machines, and flying mechas. Tails has been described as a mechanical prodigy who rivals Dr. Robotnik; however he has yet to realize his full potential. Additionally, by spinning his two tails like a helicopter rotor, he has the unique ability to push himself through the air to catch up with Sonic. However, when he takes to flight, he tires quickly. More recently, Tails has helped Sonic (more specifically, the player playing as Sonic) by giving him hints and tips on how to play the game, such as how to control Sonic and what will happen when Sonic gets certain power-ups.

In Super Smash Flash
Tails, along and, is a starter character in SSF. He got moves from games he protagonist alone just like Tails Adventure.

In Super Smash Flash 2
Tails reappears in the sequel with a wide arsenal of new attacks, techniques, and gadgets. Like all the Sonic characters that have returned so far, he did not receive a sprite change or a recolor for his return. He is ranked 14th in B+ tier on the current tier list.

Trivia

 * Though he is not playable in the Super Smash Bros. series, he is one of four Super Smash Flash characters to later have a costume for Mii Fighters based on him in Super Smash Bros. for Nintendo 3DS / Wii U. He shares this distinction with Mega Man X, Lloyd, and Knuckles.