Twin-tailed Miles Prower is the young son of SEGA Consumer Products CEO Ludmilla Prower. Within the first few months of his life, the boy demonstrated an uncanny level of intellectual aptitude, which increased at a breakneck speed; by his second birthday, the baby was already designing his own vehicles and robots. At the start of series, little Miles is living at his mother's summer home on sparsely-populated Cocoa Island under the care of AI nanny NICOLE and SIR-series security robot Gizmo while his mother is away on Earth, keeping in touch with her by Lasercomm.

Most of the kids on Cocoa Island, often feeling humiliated due to the talents of the young prodigy, took out their frustration by mocking "the little mutant" and destroying his inventions when they could. Because of this, the toddler whipped up obstacles around Poloy Forest to protect himself.

One day, Sonic visited the island and was discovered by the cub, who followed him around in secret. Finding the plane, Miles repaired it, upgraded it, and gave it a new paint job. When the Hedgehog discovered the toddler and his handiwork, the two quickly became friends; Sonic also gave him the nickname "Tails" on account of his extra tail.

Tails uses his physiological abnormality to his advantage, being able to use his tails as natural rotary blades to enable flight or to scoot across the ground the way an airboat glides across water.