American Toad

Although I do admit I was mostly going by memory of this photograph, I would disagree with you. This animal is not nearly large enough to be a green frog, and looks to me like it lacks the visual characteristics of either a green frog or a leopard frog (namely an elongated, pointed rostrum and to a lesser extent, body posture). Another point, of which you had no means of knowing, is that I would commonly find American Toads on my porch (which is where this photo was taken) and only once in the five years I lived there did I find any frog on my porch by its own choice. Lastly, if I had more/better pictures of this organism, I would have included them.