Miles Prower, known to almost everyone as Tails, is a young anthropomorphic fox who serves as a central character in the anime Sonic X. He is defined by his most distinctive physical trait, two large, fluffy tails, which set him apart from other foxes. His fur is primarily a warm yellow-orange color, with white patches on his muzzle, chest, the tips of his ears, and the ends of his two tails. He has bright blue eyes and typically wears a pair of red and white shoes along with white gloves. This appearance marks him as a character from Sonic's original world, a separate dimension parallel to Earth, who is pulled into the human world during the series' opening events.

In terms of personality, Tails is depicted as exceptionally brave and highly intelligent, with a natural gift for understanding, repairing, and constructing complex machinery. He demonstrates an aptitude for engineering that rivals even the series' main antagonist, Doctor Eggman. Despite his young age, he is a skilled and resourceful fighter who does not shy away from danger. However, his core personality is also marked by kindness, humility, and an earnest desire to help his friends. While he is an astute combatant, his confidence sometimes wavers, especially early in the story, often leading him to rely on the support and encouragement of those he looks up to.

At the heart of Tails's motivations is his profound admiration for Sonic the Hedgehog. Sonic is his best friend and his greatest hero, and Tails is driven by a desire to be useful to him and to prove himself as a capable ally. He works tirelessly to support Sonic's reckless but heroic charges, often providing crucial technological support or aerial backup. His role in the story is that of the loyal sidekick and the team's technical genius. He is not just a passenger on Sonic's adventures; he actively contributes by piloting and upgrading his beloved plane, the X-Tornado, and by inventing gadgets that help the group overcome obstacles that cannot be solved by speed alone.

This role brings him into key relationships with several characters. His bond with Sonic is the most significant, a brother-like friendship where Sonic's confidence inspires Tails to be brave, and Tails's ingenuity provides Sonic with the tools he needs to win. He also forms a strong and important friendship with the human inventor Chuck Thorndyke, who becomes a mentor figure of sorts and helps him with his engineering projects, most notably in the construction of the X-Tornado jet. He works alongside other allies like Knuckles the Echidna and Amy Rose, often serving as the calm, intelligent center of the group.

Throughout the course of Sonic X, Tails undergoes meaningful development. He begins as a character who, while talented, often doubts himself and looks to Sonic for direction. As the series progresses, he becomes more self-reliant and confident, stepping up to take on challenges independently. His experiences in the human world and the threats they face force him to grow from a sidekick into a true hero in his own right, capable of making tough decisions and leading when necessary.

Notably, Tails possesses several remarkable abilities derived from his unique twin tails. He can spin them rapidly like a helicopter rotor, allowing him to fly and hover in the air for extended periods. He can also use this spinning motion to create gusts of wind for attacks, a technique sometimes called the Tails Swipe. When on the ground, he can run at superhuman speeds, and he is proficient in the Spin Dash technique, curling into a ball and launching himself forward at high velocity. Beyond his physical capabilities, his greatest power is unquestionably his intellect. He is a mechanical prodigy, constantly modifying the Tornado into new forms like the X-Tornado and creating other advanced vehicles and devices to aid his friends in their battles against Doctor Eggman and other threats.