Name that Critter

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.