What's the biological explanation for the clic ALIEN or Grey?

Well, if Greys exist, they would most likely have a lower general body m is because of (other than your answer) malnutrition. I have read across many websites that they're slaves to the Draconian and other reptilian races. The reptilians are generally regarded as very violent and cruel, so if the Greys are slaves to the reptilians, they would most likely be treated very badly.