Very possible they are Nephilim..Something that has had me puzzled for years is Demons will start appearing to people as flesh and blood beings and matter of fact they will have the power to take human life in the last 42 months. I rather suspect Science will have managed to open the door to another dimension allowing them in...
There are a few trains of thought that the 200 Million Man Army in Revelation 9:16 is demonic and not human. I tend to lean in that direction since the logistics to just feed, arm, clothe a 200 million man army seems impossible by human standards.
There are plenty of documentaries out there that our wonderful gov’t opened up doors/portals way back in WWII and this has been going on for awhile.
Evil just keeps ramping up.
“I rather suspect Science will have managed to open the door to another dimension allowing them in...”
Or...
maybe they are already here and have been all along. Here... procreating and interbreeding... right alongside with humankind.