more detail on hybrids:

6But you from the beginning were made spiritual, possessing a life which is eternal, and not subject to death for ever.

7Therefore I made not wives for you, because, being spiritual, your dwelling is in heaven.

8Now the giants, who have been born of spirit and of flesh, shall be called upon earth evil spirits, and on earth shall be their habitation. Evil spirits shall proceed from their flesh, because they were created from above; from the holy Watchers was their beginning and primary foundation. Evil spirits shall they be upon earth, and the spirits of the wicked shall they be called. The habitation of the spirits of heaven shall be in heaven; but upon earth shall be the habitation of terrestrial spirits, who are born on earth. (24)