Yep, after closer examination, I'm convinced it's not a copperhead; just not sure what it is. But besides the shape of the head, the slender body and tail, the eyes are just round as a ball, and I can find no evidence of fangs at all.
That is definitely a corn snake. My boys caught one here a couple weeks ago. They are a rat snake closely related to the gray rat snake. I kept one for a couple years as a pet while I was in college.
Here's a couple copperheads I kept in a terrarium for a while (notice the vertical pupil on the second one):
Oh, ALL the copperheads I have see are strangely FAT in proportion to their body. Of course curled up, you really don't have a clue. But then, if I think about it, most copperheads I have seen were always on the move (or attack). They are IMHO very aggressive snakes...
-Mike Z.
It was probably a corn snake. They can be somewhat pugnacious when cornered (I once tangled with a cousin rat snake. There is still some debate as to who caught who ). Jay
Don't know if they range down to Texas but your snake looks a bit like an Eastern Milk Snake. They are often mistaken for Copperheads. Eastern Milk Snake