Fr. Barron on the film Noah:
The references to nephilim are strewn throughout the Book of Enoch, the last book that was rejected from Roman Catholic biblical canon (but still held as canon in Coptic Catholicism). Many of the Church Fathers wished to include it in the bible, while others believed it to be too complicated and apocryphal for inclusion. I have blogged about it before, and would advise anyone who has read the bible to also be acquainted with it.