I once saw a marbled snakehead (also known as an Asian Snakehead) in a pet store that was three feet long and had to weigh over ten pounds. I've had snakeheads grow from 4 inches to a foot long in a 55 gallon aquarium in just one year. A rule of thumb is the bigger the body of water, the bigger the fish will grow. These fish are piscavores: they eat any other fish that fits in their mouths. The DNR has reason to fear them. Still, I wouldn't mind hooking one...