The Distorted Ones

The Distorted ones are extra-dimensional aliens of extreme numbers. They are the only known organism that is completely immune to both darkness and light. They were first seen in the corner of the milkey way where they consumed an entire Mars fleet in a matter of hours. They appear to act as a hive mind, but individuals have broken off and grown their own sentience. They are constantly evolving and changing, but de-evolving at an equal rate, so they remain in a constant blobby state, mouths in unusual places, tentacles everywhere, grey squidgey flesh everywhere.

They (mostly) never intend to kill, they just suffocate unfortunate passerbys using sheer numbers.