I was out in the garage yesterday and found this large, attractive moth resting on the window blinds. According to my handy NWF Field Guide to Insect and Spiders of North America, this is a male Polyphemus Moth. It must be a young one, because it says they can have a wingspan up to 6". After I took these pictures, I let it go and it wasted no time getting as far away from me as possible, high in a nearby tree. In its little moth brain, I'm pretty sure it thought I was going to eat it at any moment. And I almost did. It looked delicious! Yum.
I caught a Imperial Moth several years ago that was about this same size, and it was a brute! It was all I could do to hold on to it... a very powerful critter.