The boy who played Damien, Harvey Stephens, was chosen because of the viciousness with which he attacked during the film auditions: he even kicked the actor in the balls!
The Catholic Church and Vatican were very opposed to the making of this movie, which they felt ‘passed the wrong message’.
The release was heralded by the 3 ‘sixes’ since it was June 6, 1976, and many viewers were scared mindless, also due to the religious and superstitious connotations the film brought.
Scene where the monkeys attack the car in the Zoo required a lot of work. They had to actually take the baboon chieftain inside the car, only then the rest of the monkeys went absolutely crazy and the sequence where they lash at the car is quite real!
For the falling fishbowl scene, only dead sardines were used. They have been painted orange instead of actual goldfish, because director Richard Donner did not want to kill just for the filming.
A fact: Sales of Rottweiler dogs in the United States had a huge surge, since they gained great popularity with this movie.
Movie title underwent change from ‘Antichrist’ to ‘The Birthmark’, and everyone was circulating stories that this production fell under a heavy curse. Many strange things indeed did occur. Lead actor Gregory Peck and screenwriter David Seltzer boarded 2 different airplanes to the UK, but BOTH got severely hit and damaged by lightning! During producer Harvey Bernhard’s stay in Rome another lightning barely missed him. The black dogs (Rottweilers) used in the movie viciously attacked their trainers on more than one occasion, without any cause. The lodge where director Richard Donner lived was bombed by the IRA, and he even got hit by a car. An airplane that actors were meant to board, but missed by chance crashed, killing all passengers on board. Another time, the crew barely survived one more head-on car crash. Finally the special effects artist John Richardson was maimed and his girlfriend beheaded, which again was blamed on the curse. Those are just some of the things which haunted the filming.
It is known that a multitude of writers, actors and technicians refused to work on this project because of the subject matter.
This movie actually was the performance that paid most during entire Gregory Peck career.
Kid Harvey Stephens' original blond hair was dyed black to make him look more “evil” as Damien.
Twice the budget of film ws actually spent on promotion and advertising.
Mr. Terry Walsh, the stunt double of David Warner, received heavy injuries during the ‘dog attack’ sequence.
Archaeological dig locale claimed to be the Megiddo was a real dig allright, just not real Megiddo; it was in the Old City of Jerusalem, not far from the Temple Mount.
Actor Gregory Peck said that he agreed to play the father because when his son Jonathon committed suicide (in 1975) he was not there, and felt guilty. The kind of guilt the main character was meant to have…
It is said that David Seltzer's script of the accursed movie was inspired by the Bible, or the Revelations part of it, be more precise. In the Christian tradition, when the morality declines, the world will have an Antichrist/devil rule it for some time before the end of the world.
Actor David Warner was suffering terribly from a skin condition called psoriasis during the making of the movie. His pain was so much, that he had fly to Switzerland for treatment.
For the spooky decapitation sequence, 5 cameras were used.
Until it was surpassed by Star Wars: A New Hope next year, Omen was 20th Century Fox's best revenue movie.
Interesting life fact: taxi driver that takes Thorn around Italy was a son of a real-life Mafioso. He almost lost his fingers when Gregory Peck accidentally slammed a car door on his hand!
When the night came at the Longleat Safari Park, after the shooting was done, a zookeeper was killed at the lion section, making everybody talk about the persistent curse on the movie for the next few months.