Hi Derek.
The last photo is perfect to me. Maybe a little too light. I don't know if you can setthe shuttertime of your cam, but if you can you can try to have a short shuttertime. As a result your pics will be much sharper. A tripod works ok too, with the benefit that you don't have too use the flash. This way the colours of your pictures will be so much warmer! (compare the first and the second photo)
Good luck with your pictures. Beautifull snake by the way