Snake or Gecko piece?

When I took this picture I was actually inside someone's private property, it was just a vacant lot and there were just a few bricks laying there and half grown grass, so not really an important private property and the owner probably doesn't go there much, but given that I'm a blonde girl who speaks no spanish at all, I assumed that if I got caught, I could just tourist my way out of any kind of trouble.

I was able to take some pics from this set, not only this one. I guess that at some point when the owner of the ground cared a little bit about his place maybe he allowed good street artists to come here and practice because there were around 5-6 different pieces with different styles and coloring.

This one for me is a gecko, although it is quite clear that it's a snake, notice the nostrils and the fangs, it's definitely a snake but to me, and maybe because I am a pacifist and a dreamer, I choose to believe it is the former.