In a nutshell: The following passages all refer to the same transgenic experiments carried out by the Nephilim. They say that various animals DNA were mixed together, including the DNA of humans. Now, they also say that the giants carried out these experiments on reptiles, so no doubt they mixed the DNA of reptile with human and created the beings we know today as reptoids.

I also have no doubt that dinosaurs were created by the Nephilim also. A T-Rex is more physiologically similar to a chicken, according to latest research, this is because the Nephilim cross-spliced the DNA of large flightless birds with large crocodiles.

"And their judges and rulers went to the daughters of men and took their wives by force from their husbands according to their choice, and the sons of men in those days took from the cattle of the earth, the beasts of the field and the fowls of the air, and taught the mixture of animals of one species with the other, in order therewith to provoke the Lord; and God saw the whole earth and it was corrupt, for all flesh had corrupted its ways upon earth, all men and all animals." Jasher 4:18

If we look at this last line, "for all flesh had corrupted its ways upon earth, all men and all animals". This means that, not only was the flesh of animals corrupted via DNA mixing, but also of men. The Nephilim had mixed the DNA of humans with animals also.

We read again about the corruption of flesh among humans and animals in the Book of Jubilees:

"All flesh corrupted its way. Humans, herd animals, wild animals, birds, and everything that walks on the earth – they all were corrupted from their natural order."

"And they began to sin against birds, and against animals, and against reptiles, and against fish, and they devoured one another's flesh, and drank the blood from it." Enoch

"The earth was full of violence. God looked upon the earth and saw that it was corrupt, for all flesh had corrupted its way upon the earth, so God said to Noah, "The end of all flesh is coming." Genesis

In the fragmented Book of Giants, it says the same thing.