Eeek, What is it?!

Summer in Florida brings on not only the heat, but some cool creatures as well. I found this guy outside my garage chasing a lizard up my brick wall. I guess I spooked him because he took refuge under the wall a/c unit for a whole day. I tried to coax him out with some lettuce, he was not interested.

I know it's a reptile, but what kind? Iguana, Bearded Dragon, someones missing pet, not sure? He was about 12 inches long and had some greenish/yellow stripes under his neck.  I was hoping to get more photos, but the next time I looked, he was gone. I now have a hole in the ground about his size, at the bottom of that wall. I wonder if he dug himself a tunnel to live in? Anyone have any idea what kind of lizard he is?