what kind of spider is this
All spiders are venomous, and they may bite when harassed or provoked but it is no worse or harmful than a bite or a sting from other insects. Fortunately, most spiders have to really be provoked into biting. The only spiders that are considered "dangerous" in Texas are the Black Widow spider and the Brown Recluse spider. Your spider is neither of these.
Your spider is one of the orb-weaver spiders of which there many species.
It is referred to as the Texas "Death's head spider" - Eriophora ravilla.
If you closely look at the white marking on the back you can see what could be imagined as two eyes, a nose and a long chin. Perfect for Halloween don't you think.
Orb weaver spiders, also referred to as writing spiders, are he most common group of builders of spiral wheel-shaped webs often found in gardens, fields and forests. Sometimes it looks like they write something in the middle of the web when they join the center together, thus term "writing spiders."
Here is a publication on spiders for your general information: