I think it will prove to be some kind of garter snake. There are a lot
of different ones around. It looks similar to one here in Texas, but
the one here has a more pronounced orange stripe down the back. There
is another here that is checkered - very checkered - without the
stripe. Harmless and beneficial, but in the cobra family. I suspect
there is a lot of variation in appearance even among the same species,
so it may be hard to find an exact match for the one in your photo.
Texas Zone 7b, USA