I work as a professional photographer, so my point of view is from that avenue. It is inevitable to have images stolen it is going to happen. I would not bother to place the water mark on the animal but place it off to the side yes I know it can be pulled in no time. I would however add copyright notices and Usage terms and your contact info embedded into the file (which is void of all of this currently)
The other security method is low rez small files never place any file on line that is usable for anything other than on line.
I routinely have files reposted somewhere the last one was at christmas from here. reposted on Facebook complete fluke I found it. I tagged myself on the file and left it alone. No harm no foul I take it as a compliment. If you try to pass it off as your own file or in your case as your own snake and the usage terms are broken you are going to pay for it. I charge 2500$ per image for infringement quite fair when you look at copyright violations I have 5 or 6 times asked for this and got it out of court with little fight it was pointed out that the file still has my metadata and terms on it the violation is clear and well...
My opinion.