help identify caterpillar!!

[mantisdragon]

hello, I found this caterpillar on the sidewalk. It is about 2 and a half inches long. When I picked it up it wiggled around rather crazily. Underneath it has dark brown almost redish blotches. Does anyone know what kind of caterpillar it is? Also what does it eat? I would like to keep it alive so it can cocoon and turn into an adult.

Location is Maryland, near Annapolis.

[img src="i1063.photobucket.com/albums/t512/Dragonfly_64/DSCN8961_zpswtnondzq.jpg" src="" alt=" "]

[img src="i1063.photobucket.com/albums/t512/Dragonfly_64/DSCN8960_zpsweqm6of0.jpg" src="" alt=" "]

[img src="i1063.photobucket.com/albums/t512/Dragonfly_64/DSCN8954_zpsjmxauxxu.jpg" src="" alt=" "]

[oehlkew]

It appears to be a mature Catocala (underwing moth) larva. might even be Catocala ilia. They usually feed on oak. If you put it in a glass jar with a couple of leaves, it will probably fashion a very flimsy cocoon out of a few silk threads and the leaves, and then will yield a moth in about 3-4 weeks. I am pretty sure it is done feeding.
Bill Oehlke
Hope you will post picture of the moth when it emerges. The thrashing about is also typical of Catocala larvae.

[mantisdragon]

I will post some pics when it emerges.