Nephilim

"But now the giants who are born from the (union of) the spirits and the flesh shall be called evil spirits upon the earth, because their dwelling shall be upon the earth and inside the earth. Evil spirits have come out of their bodies. Because from the day that they were created from the holy ones they became the Watchers; their first origin is the spiritual foundation. They will become evil upon the earth and shall be called evil spirits. The dwelling of the spiritual beings of heaven is heaven; but the dwelling of the spirits of the earth, which are born upon the earth, is in the earth. The spirits of the giants oppress each other, they will corrupt, fall, be excited, and fall upon the earth, and cause sorrow. They eat no food, nor become thirsty, nor find obstacles. And these spirits shall rise up against the children of the people and against the women, because they have proceeded forth (from them).
- 1 Enoch 15