This is an interesting question. Who created the creator. As per the human thought, God is the God of Gods. That means God is a self made God. He Born of Himself. We do not have any idea even in the Bible, who created God.
It is considered as inappropriate to ask the creator about his creator. "Who am I" to ask such a question. And we are not expected to ask such question. It shows our arrogance.
The only way to know the creator of the creator is to ask the creator.