Sphecodina abbottii. That's what was eating my concord grape vine. The skin eventually turns brown leaving large evenly spaced green spots all along its body. I suppose it's mimicking a snake that way.
Since the day I took this photo I haven't been able to find it again so hopefully a bird didn't get it. I've read they can be very uncommon in their range, but I know the forests here are all abundant with grape vines. I'd say most forests have a Vitis species in them it's just that they don't produce a lot of fruit unless you prune them severely each spring.