Is Mara a real being or something internal, produced by our own minds?

I have heard both interpretations, for me it would make more sense to be something from the mind as there is no creator God or its opposite in Buddhism, the image of a "temptator creature" like Satan sounds strange when we think about impermanence, on the other hand, some suttas that mention Mara may fit better with the concept of an external creature, I know this interpretation is questionable, so I'm making the question!