Does the creator have to be a god?
For example, millions of years from now, an average IQ trainee lab technician called Andy might accidentally send something back in time, triggering the Big Bang whilst destroying their own universe - The entire thing could be a loop of our own creation.
To add even more mind bending philosophy to this theory, since all possibilities exist in a multiverse - this has actually happened in one of them, creating the origin point for all multiverses