Pig frog or bullfrog

My husband, who usually leaves for work before dawn, reported seeing a large
green frog in the driveway several days ago. Coming home late last night
from an evening with friends, I saw the culprit myself, on the driveway in
the lit area. He's solid dull green, about 6-7" long, and looks like a
photo of a pig frog I found in several of my books. I approached him slowly
from behind, and suddenly he noticed me and flew off into the foliage beside
the driveway, leaving a trail of fluid (presumably urine?) behind. I am
protective of frogs, toads, and snakes (even rat snakes, which tend to eat
my Barn Swallows ), so I wasn't trying to hurt him, just get him out of
the way so I could put my car in the garage.

I suspect he's keeping my minnow population down in the inground pond. I
doubt he can get up into the stock tank ponds - there's no access. So far I
haven't noticed any goldfish loss in the inground pond.

Gail
near San Antonio TX USA