In this area, the likely candidates are pronghorn and white-tailed deer.
Not sure if there's any chance of IDing this to species level, since there are 14 species in Texas and apparently ID requires capture and examination, but hey...
This is definitely a male--he's got the little hooks on his front two legs, and of course he was out in the open clipping along, likely trying to avoid becoming someone's lunch. Biggest wild tarantula I've seen!
At least three individuals. Observed one stealing fish from an (Osprey Pandion haliaetus).