There were Giants in the Days of Noah, for the Watchers Begat Children with the Daughters of Men
And they Taught the Mixture of Animals of One Species with Another, and All their Ways were Corrupt, so God Sent a Deluge to Destroy All on the Earth, Even the Tall Trees were Torn up by their Roots, and Sank into the Abyss
Genesis 6:4, Torah
There were giants in the earth in those days [of Noah];
[Book of Enoch 7:2 - 4], Torah
And [so the daughters of men] became pregnant and bore large giants. And their height was three thousand cubits. These devoured all the toil of men; until men were unable to sustain them. And the giants turned against them in order to devour men.
[Book of Enoch 9:8 - 9], Torah
And they went into the daughters of men together, laid with those women, became unclean, and revealed these sins to them. And the women bore giants, and thereby the whole earth has been filled with blood and iniquity.
[Book of Enoch 10:15 - 16], Torah
[And so the Lord said to Michael,] "Destroy all the souls of lust, and the sons of the Watchers, for they have wronged men. Destroy all wrong from the face of the earth and every evil work will cease."
[Book of Enoch 10:1 - 2], Torah
And then the Most High, the Great and Holy One, spoke and sent Arsyalalyur to the son of Lamech, and said to [Noah], "Say to him in My name; 'Hide yourself.' And reveal the end to him, which is coming, because the whole earth will be destroyed. A deluge is about to come on all the earth; and all that is in it will be destroyed."
[Book of Enoch 54:7 - 8], Torah
[For] in those days, the punishment of the Lord of spirits will go out, and all the storehouses of the waters which are above the heaven and under the earth, will be opened. And all the waters will be joined with the waters that are above the heaven.
[Book of Enoch 83:3 - 4], Torah
[And thus,] I, [Enoch], saw in a vision how heaven was thrown down and removed, and it fell upon the earth. And when it fell upon the earth, I saw how the earth was swallowed up in a great abyss, and mountains were suspended on mountains, and hills sank down upon hills, and Tall Trees were torn up by their roots, and were thrown down, and sank into the abyss.
There was a Tree in the Midst of the Earth - the Height Reached to Heaven
And a Watcher Came Down from Heaven and Said, "Hew Down the Tree and Leave the Stump of its Roots in the Earth"
Daniel 4:13 - 14, Torah
[Then] a Watcher and a holy one came down from heaven; he cried aloud, and said thus, 'Hew down the tree, and cut off his branches, shake off his leaves, and scatter his fruit, let the beasts get away from under it, and the fowls from his branches.