For the geek-impaired: Tails Wikipedia page

He’s the youngest character out of Sonic’s crew, well, as far as I know, anyway. I lost track of all of the “-blank- The -blank-” characters after Sonic Adventures. According to the first Saturday morning TV show, Dr. Robotnik pollutes the fark out of the planet wherever he goes, so Mama Tails probably got exposed to something-nasty-or-other, which resulted in Tails’ deformity. Yeah, he’s a mutie, alright.

That said, it worked out well for him, after all, he’s the only fox I know of can fly unassisted (Fox McCloud has a spaceship, so he doesn’t count). At least he didn’t end up like Jeff Goldblum in The Fly or Mrs. “OH NOES I can’t touch anybody EVAR” Rouge from the X-Men or those schlong-monsters that freaks are making with the Spore Creature Creator. Heaven only knows what freaks exist in the dark underbelly of the Sonic Universe.

Yes, I’m bored.