Tomatoville® Gardening Forums - Is this a giant aphid?

I found a bug today in the soil around the roots of my green bean plants while I was pulling them to start a new crop. I was having a hard time getting the camera to focus and was hurrying to beat the rain so I apologize for quality of the photo. I found a total of 2 while pulling the plants, one flew away, the other is in my hand. Looked like an aphid, but was about 10x the size of any that I've seen on my plants before. It was about the size of a BB. I've scoured the Internet and can't find anything that looks like it. It was almost neon green and stuck out like a sore thumb against the black potting mix. In the picture I have it laying on its side and you can see that it's back has "spines" on it. Also the profile of the insect was a lot taller than I've seen in aphids which seem to be more flat profiled. Also it's legs were running incredibly fast while trying to gain its footing. Most aphids I've seen seem to move fairly slowly. Could this just be an aphid that got giant? My only other thought was that it looked similar to a miniature katydid.