It's mind-blowing to think about, but there are a million different ways that our bodies could have potentially turned out when we were born.
While a lot of the genetic anomalies we can come across are rare, that still means they happen to somebody and when so many of them are possible, there's really no telling how any of us will turn out.
Of course, the rest of the animal kingdom works the same way, which can sometimes make it tricky to tell whether we're witnessing a genetic mutation or an entirely undiscovered species when a creature looks unusual enough.
But even when we know what's going on, that doesn't mean we can't be amazed by it.