That’s what I was thinking. Alligator gar!
BTW, those live in the Southern US. Have fun at the swimming hole!
If that won’t fit your tank and you don’t mind importing, the Goliath tigerfish may fit your bill a little too well.
Having never seen one before, you may well imagine how quickly I exited the river when I first saw a gar.
I once had a Leporinus fasciatus in my 29-gallon tank that, over time, ate every single one of his tankmates and grew to about 8" before I finally had to give him away.
Well, since he was a fascist leopard, I think he’d call it Lebensraum.