The Rio Grand is full of alligator gar. I’ve seen them roll along side the boat when I was fishing in South Texas. They are not a danger to humans.
Would I eat one? No. Nor do I want to eat the needle nose gar (small cousin fo the alligator gar). But some people do. But for that matter some people eat Carp. NOT ME.
Gar are VERY tough to clean. I did it once (36” fish.) That was the last time for me, unless I was starving. Smoked, the meat was actually pretty good, just too much dang work.
My Dad caught one over 6’ long. Most impressive!
Asian Carp are actually quite good tasting, out of decent water. They are filter feeders and eat plankton, so contaminants like mercury are usually very low. The small bones are a pain, though. Possibly a pressure cooker would cook them out.