Enoch, in his sleep-vision that has been called the 'Animal Apocalypse' (of 1 Enoch's "Book of Dreams"), "saw heaven above, and behold:  ... a star fell from heaven [Azazel], and it arose and ate and pastured amongst those oxen [the righteous Sethites, descendants of Adam's son Seth]. And after this I saw the large and the black oxen [the wicked Cainites, descendants of Adam's son Cain], and behold, all of them changed their pens and their pastures and their heifers [women], and began to moan [breed], one after another. And again I saw in the vision and looked to heaven, and behold, I saw many stars [Shemihazah and the rebellious Watchers], how they came down and were thrown down from heaven to that first star [Azazel, whom they worshipped and who taught them Heaven's secrets], and amongst those heifers and bulls [humankind]; they were with them, pasturing amongst them. And I looked at them [the Watchers] and saw, and behold, all of them let out their private parts like horses and began to mount the cows of the bulls [the 'daughters of men'], and they all became pregnant and bore elephants and camels and asses [the "giants" — creatures, physically unlike either of their parents, at once of great stature and/or pridefully stubborn, repulsive]. And all the oxen [humankind] feared them and were affrighted at them, and [they] began to bite with their teeth and to devour, and to gore with their horns. And they [the Watchers and their giant-sons] began, moreover, to devour those oxen [the righteous and wicked alike]; and behold all the children of the earth began to tremble and quake before them and to flee from them ... (1 En 86:1-6)  But perhaps the Watchers' most grievous sin was to teach and instruct humankind, blasphemously, in various forbidden arts, sciences, and celestial "secrets" or "mysteries" of the true heavenly "gnosis" or knowledge — especially that Wisdom possessed by Azazel (Satan), who taught them also the secrets of war (from magic, metallurgy, and weaponry to seductive ornamentation, jewelry, and cosmetics) — all of which ultimately, though not surprisingly, brings down the wrath of Heaven.