The Necrons are a fictional alien race in the Warhammer 40,000 universe. They are a race of robotic, undead beings who were once a powerful civilization that ruled the galaxy, but were forced into hibernation by an unknown enemy. They have since awakened and are seeking to reclaim their former glory. They are known for their immortality, advanced technology, and their ability to bring fallen warriors back to life. They are powerful and relentless enemies, feared by many in the Warhammer 40,000 universe.