The cats dragged this poor guy up to the patio. He died of his injuries a while later. I was sad because these are lovely snakes - calm, companionable and usually found hanging out in trees.
He was about 3 feet long, uniformly green with a lighter whitish belly.
Answer below the fold...
Answer: Rough green snake. [Opheodrys aestivus]. They like to eat grasshoppers, crickets, caterpillars and spiders. Useful to have around.