Are the Watchers in 1 Enoch based on Mesopotamian mythology?

Partly — and being honest about which part is the whole point.

In 2010, the scholar Amar Annus published a forty-page argument that the Watchers of Jewish tradition — the angels who descend, take human wives, and father giants in Genesis 6 and 1 Enoch — are a Jewish reworking of the apkallus, the antediluvian sages of Babylonian legend. He laid the case out in eight numbered theses and defended it with evidence ranging from cuneiform incantation texts to the Book of Genesis.

Here's the catch for anyone trying to fact-check that argument with Hebrew, Aramaic, and Greek biblical texts: a large share of his evidence is Akkadian — the apkallu lists, the Erra Epic, the Uruk King List, Babylonian incantation series, and more. None of that can be verified or disproved by a database built on the Hebrew and Greek Bible plus the Dead Sea Scrolls. So a fair review has to say up front: this half of the argument is out of reach, neither confirmed nor refuted, just reported as his claim.

What can be checked is everything he draws from the Hebrew Bible, Aramaic sources, and the Dead Sea Scrolls — Genesis, Numbers, Deuteronomy, Daniel, and the Qumran Book of Giants fragments. And that check turns up a mixed record. Some of it holds up well: the Septuagint really did merge two distinct Hebrew words (nephilim and gibborim) into a single Greek word, γίγαντες, which gives his central move on Genesis 6 more ancient support than he even claims for it. Two of the three giant names he cites from the Book of Giants are genuinely there in the ink of the Qumran fragments.

But some of it doesn't hold up. He describes Og of Bashan as having "gigantic size of 9 cubits" from Deuteronomy 3:11 — but that verse measures Og's iron bed frame, not Og himself; the Hebrew grammar (feminine suffixes agreeing with the feminine noun for "couch") settles that the nine cubits belongs to the furniture. He calls the Nephilim of Genesis 6:4 the direct offspring of the divine-human union, when the Hebrew text actually separates the Nephilim (who "were on the earth") from "the mighty men" born of that union — a common ancient reading, but a reading, not what the verse states outright.

"The Nephilim were on the earth in those days, and also afterward, when the sons of God came in to the daughters of man and they bore children to them. These were the mighty men who were of old, the men of renown." — Genesis 6:4

That's the shape of an honest review: name what can't be tested, test everything that can be, and report both the places the argument holds and the places a reading of the text got carried into the argument as if it were the text's own content.

The full study works through all eight theses point by point — where the Hebrew Bible backs him up, where it doesn't, and exactly where the evidentiary ceiling sits. Read the full study: Annus on the Origin of Watchers — Testing the Hebrew Half