Cool Dave, years ago on the Caney there was a massive one that showed up for a couple of spring seasons, hung out at Happy Hollow. It would hangout under my drifter & we were guaranteed not to catch a fish untl we got to the riffles at the rest area & it couldn't get through.
I was trying to get through some folks on one float & one guy was being an arse & told me to go behind him in 5" of water, backstroked a few times on the oars, that big thing came out from under the boat & the guy took off running, told him i didn't want sick my fish on him the next time
Grumpy