Your posting reminded me...
My dad and I used to go fishing at Possum Kingdom Lake, near Mineral Wells and Graham Texas. His co-worker owned a cabin there on a slough. One time we went out night fishing between the cliffs near the dam, hanging Coleman lanterns over the sides of the two boats to help lure the fish. Two boats, 7 adults and me at ~ 13.
It was a kinda creepy, no wind, moonless night... and then the guys started talking about how we were so close to the dam that maybe the bass were staying away because of the big catfish. They talked about divers who have to go down and clean out the flow vents occasionally have reported seeing huge catfish the size of VW Beetles.
Just Google Possum Kingdom Lake catfish to see some pics.
OMG!
I was up boating in Homosassa a few years back - and several of us went swimming in the spring with these babies... Also at Blue Springs even more years back: