The multiverse theory. The possibility that there are an infinite number of parallel universes where an infinite number of possibilities all exist at the same time.
Based on the parameters of this theory there therefore exists a universe where I am Batman. That’s pretty much all you need to know about this question.
I will add that, while an infinite number of possibilities exist, I suspect that I still have red hair in all possible universes. The key word being “possible” in this statement. It is not possible for me to have existed any other way. I mean, can you imagine a blonde version of me? No, you cannot. The laws of physics in all possible universes would prevent such a horror.
QED.
Inside the Red Head's Head 