Why Does Tails Have TWO Tails?

It always bothered my overly analytic mind trying to understand WHY Tails had two tails. Honestly speaking, Sonic was a kids' game, and as such, most kids, at least ones I knew, didn't care about such things. But since I'm a nerd I'm going to give my possible explanation to Tails' genetic malformation.

And just for fun, a dumb running sonic I animated. This is probably what happened to Sonic after finding out about Tails and his twin.

Download Content

When I was little I remember going over to my friend's house to play some SNES or Sega Genesis, passing the time away like any kid would do. Back then I remember he owned a lot of arcade ports because his dad liked those type of games the most, and with many arcade games there were codes built in to get extra items, lives, characters, etc. At least this is how I remember video games.

Nowadays I have an Xbox 360, which happens to also have a lot of arcade ports I like being released for it. The thing that's different this time though is that unlike in the past when you played something like a fighting game in the arcade and had to do some special command at the character select screen to get secret characters you're instead told to pay to download the "rights" to use the extra character. This wouldn't bother me so much if I knew that the content I was downloading was something not on my game disc, but no, in many cases you're downloading a small file that unlocks the rights to use the content that's on the disc. How can that even be labelled as download content if you're not actually downloading the content? How is this even legal either? It would be like buying a car, being given the keys to unlock it, then after getting inside being told you have to pay extra to have the steering wheel unlocked.