A Nessus Sphinx Moth (Amphion floridensis).
I found one of these clinging to a plant yesterday, and had it identified. Today, our neighbor pointed this one out sipping goo that was leaking out a wound in her White Oak tree. It seems to attract a variety of things including hornets, Red Admirals and Red Spotted Purples:
Oh, and the the copyright mark? I was experimenting. To have an image used at butterfliesandmoths.org, it needs a copyright mark. Now I have to figure out how to invert it, so I can put a white one on a dark photo. If you want the picture, take it anyway.