Nice shot. Would like for head and eye to be sharper. Seems focus is on the body. Maybe by moving to the right might have gotten the with seperation. I know this moments are exciting just something to think about. Also the OOF stick is a little distracting. I do like the photo. Wish you had posted detail info about camera settings.
Welcome aboard Les. Please do post the technical details in the future as that is very helpful in understanding how the image was made.
I agree with JP comments. Well done capturing the action. The focus looks like it is on the body to the right of the head. You want to have critical focus on the eye when possible. If you are using all the AF points in the camera, try selectively choosing one near the eye and focusing that way.
Love the pose and the colors in this one. I also like how you captured the snake's pattern. I think I would've went with a different crop to cut out some of the distracting patterns in the BG and put more focus on the subject. Quick cheesy edit below.
Steve
The motion in the tail tip is a great element, adds an additional sense of danger to the image. I think I like Steve's crop and edit, removes a lot of the distracting elements mentioned, and really features the curve in the tail in the composition.
Beauty of a snake; I'd love to see one of these some day. Previous comments are right on. A bigger lens than whatever you were using might have separated the snake from the backgound. Since I can't tell where you are from I'm not sure if the is an eastern or western diamondback... is it eastern?