In Massachusetts the snakeheads are registered as a prohibited fish, not even restricted, which means no license or permit can be obtained to own one, and a bad fine or potentially some jail time. whoever is selling these fish needs to stop selling. In some cases officials will make you physically destroy it in from of them to ensure that it does not find its way into public water ways. The snakehead is not federally illegal, but is under the Federal Injurious Fish List, which means you cannot import them or allow them to cross state, i.e. interstate commerce. this ban doesn't mean you can't own them, it just means that you can't import it or bring in from another state like New York, or Pennsylvania. Each state has its own laws, so anyone interested in keeping one of these fish should check their statute books on the legality of them. However, Massachusetts has labeled them prohibited.