Enoch 15:
The Book of Enoch, Translated by Robert H. Charles, 1912
The Creation of Unclean Spirits
8"And now, the giants, who are produced from the spirits and flesh, shall be called evil spirits upon the earth, and on the earth shall be their dwelling.
9Evil spirits have proceeded from their bodies; because they are born from men and from the holy Watchers is their beginning and primal origin; they shall be evil spirits on earth, and evil spirits shall they be called.
10As for the spirits of heaven, in heaven shall be their dwelling, but as for the spirits of the earth which were born upon the earth, on the earth shall be their dwelling.
11And the spirits of the giants afflict, oppress, destroy, attack, do battle, and work destruction on the earth, and cause trouble: they take no food, but nevertheless hunger and thirst, and cause offences. 12And these spirits shall rise up against the children of men and against the women, because they have proceeded from them."
16 From the days of the slaughter and destruction and death of the giants, from the souls of whose flesh the spirits, having gone forth, shall destroy without incurring judgement thus shall they destroy until the day of the consummation, the great judgement in which the age shall be consummated, over the Watchers and the godless, yea, shall be wholly consummated.
So demons are disembodied nephillim, and the females of them are called sirens.
There are two sirens in Zechariah 5:15 -two female spirits with stork wings.
There are succubus and incubus demons who are unclean wicked spirits who seduce men and women.
19:
19 And Uriel said to me: "Here shall stand the angels who have connected themselves with women, and their spirits [
the offspring spirits, disembodied] assuming many different forms are defiling mankind and shall lead them astray into sacrificing to demons as gods, here shall they stand, till the day of the great judgement in which they shall be judged till they are made an end of.
2And the women [
female spirits born to them] also of the angels who went astray shall become sirens."