focus and catching the tongue is wonderful, the background is not supporting your effort though. (not that i would have had the guts to get the subject to a 'nice' background ;-) )
You know you're a photographer when you're out and about and see a rattlesnake and you hope he DOESN'T get away before you get some good shots. :) Nice job!
Extreme lighting conditions meant that a better approach might have been to reduce the exposure by either aperature or shutter speed - the image appears to be washed out. It might have been a good choice to reduce the exposure and increase the color saturation using basic editing tools to increase the visual impact of this image. The subject is richly detailed which is washed out - it would have been a very good image if only a little more exposure control was used. A good entry into the challenge.