Personally I would include in a definition of sane not putting ponies in space.
Edit: On the other hand that could just be me. Prehaps I am the weird one for finding this strange.
From my understanding it came from some redoubtably crazy posts from the beta. While that was even before my time in this game, I've come to like them, and it is pretty funny. I mean once you think about it every game needs a mascot, and what else can Sins have except space ponies! 