The Nephilim are reputed to be either fallen angels (per the Bible) or perhaps Aliens who came down to Earth and co-mingled with Earthly females. Some references to Nephilim say they are the giant offspring of the mating of Aliens and Earthlings. Some people, both scientists and layman, claim to have found physical evidence for their existence.
Here are a couple of books I've read on the topic that we'll be discussing soon.
The Rise and Fall of the Nephilim, Scott Alan Roberts, New Page Books, 2012. The Nephilim and the Pyramid of the Apocalypse, Patrick Heron, Citadel Press, 2004.
There were Giants Upon the Earth, Zecharia Sitchen, Bear and Company, 2010.
