The Nephilim (from Hebr. nāpal, “to fall,” hence probably “the fallen ones”) are mentioned in Genesis 6.4 and Numbers 13.33. In Genesis, they are the children of the sons of God and human women, and are called “heroes of old” and “men of renown.” In Numbers, they are described as the giant aboriginal inhabitants of Canaan, living at the time of Moses. It is not clear why or how the Nephilim survived the Flood to become the original Canaanites; probably a duality of older oral traditions can be detected in the clash between these two texts. The Nephilim seem to share a common fate in Genesis and in Numbers, perhaps generated by their name—they exist only to die in a great destruction, either the Flood or the Israelite conquest. The Nephilim seem to be related to the Rephaim (cf. Num 13.33 and Deut. 2.11), whose name is also connected with the dead, who are also giants, and who are also wiped out by the early Israelites.
Ronald S. Hendel