the alien is standing in front of a starry sky

Intelligent ancient alien carnivores, from a solar system 50 light years from Earth arrive in 12 hours, they are top of the food chain aliens for this Galaxy, and feed upon lesser species in a totally unsustainable way, they are still high in numbers today, however will see then end of there civilazation perish in the next 150 years due to the constant requirement of food and unsaitable hunger. Great distances are travelled between stars and planets in this Galaxy constantly by the alien carnivores, who live in a perputal state of hunger, with very unforgiving odds of actually finding flesh and meat suitable for consumption en masse. The humans are preparing to defend the planet, all in favor, all in common goal. The aliens are being described as reptiles, however they are difficult to see on a dark night due to there jet black scales and skin. There isn't a normal body, the core or brain and face with eyes are at the center of the subject, with a large array of black tentacles extending out from the center