Identificaciones de rehb

I think this is a moth. It is huge- I've seen these several times in the same area (I don't know if it's the same one, or several of them), and it is easily bigger than an Eastern Tiger Swallowtail butterfly. This is the first time one has ever actually been still enough to get any kind of photo, and the light was extremely poor, and it was camouflaged so well on the ground that it was nearly impossible to pick out.

At first glance I thought this was a western king bird, so I turned around and drove back to where I saw it and took some photos. The coloring made it look like a scissor tail fly catcher but this bird does not have a scissor tail