Who knows if these creatures are real. People claim to see the exact same type of alien when they claim they were abducted. I've heard a lot of crazy theroies from them being creatures from Zeti Reticuli(Betty and Barney Hill case) to humans from the future. In the Travis Walton case all of the ufo witnesses passed the poligraph test when they claimed to see a ufo and travis being knocked out by a beam of light. Those guys must of seen something that really scared them but is it a ufo and greys idk.