Prypiatosian A

Prypiatosian A's are from the frozen world of Votosk, so cold that temperature is just an abstract thought. Due to these conditions, Prypiatosians have evolved to become heat producing, nuclear powered, hydrogen based lifeforms. Their nuclear life force means that they live for hundreds of thousands of years, and never run out of energy as long as they live. A small group of them upgraded their armor and went to the Andromeda galaxy, becoming Prypiatosian B's. The A's still live on Votosk, but have heard of a planet that produces it's own nuclear energy, and that nuclear energy is used as power there. They don't know that all planets produce some amount of nuclear energy, and so are coming to the Earth in particular. They are using their powers to fly through space, and will arrive soon. Some are coming for a better life, some to help the inhabitants, and some for not as noble purposes. It is unknown what humans will do when they arrive, though general panic is expected.