Not to be the voice of dissent, but both snakeheads and eagles can be kept in the U.S. with the proper permits. Of course, the permits for snakeheads are next to impossible to get for an educational institution or zoo/aquarium, let alone a private individual. And in regards to keeping eagles, certain eagles may be kept with the proper falconers license, but these licenses take at least five years to obtain.
So in short, it is possible to legally obtain a snakehead, but your chances or acquiring the proper permits are slim to none.