Audio problem: Near the end of the movie, when the Ambassador is dragging the child up the aisle of the church, in several spots you hear the child scream but his mouth isn't open. (01:45:35)

The Omen (1976)
Ending / spoiler
Directed by: Richard Donner
Starring: Gregory Peck, David Warner, Billie Whitelaw, Lee Remick, Harvey Stephens
Robert Thorn (Gregory Peck) finds the triple 6 on his son, Damien's head, beneath his hair. The nanny tries to kill Thorn but he kills her. Thorn rushes to a church with his son and the police pursue. In the church, he's about to kill his son with the daggers and the police shoot. For a moment, we don't see if Thorn killed his son or not. The scene changes to a funeral and we see young Damien turn around and smile to the camera...
Malebolgia
Trivia: Richard Donner was originally wary of sending the script to Gregory Peck. Combined with the original ending, in which Robert kills Damien, and the fact that Peck's son had recently committed suicide, Donner thought offering the film to him was distasteful. But to Donner's surprise, Peck agreed relatively quickly to do the film.





Answer: It's possible that the mark didn't appear until Mrs Baylock showed up and began teaching him about his heritage. The mark of the devil is said to appear only when Satan accepts a follower, and up until Mrs Baylock appears, Damien is a normal boy. Yes, he's the devil's son, but he knows nothing of his evil nature until she starts teaching him. In fact, at one point, Robert mentions that he knew every inch of Damien's body since he raised him and never saw anything, so more than likely the mark didn't appear until Damien had areas on his body where it could be hidden more easily.
dewinela
But it's a birthmark. He had it when he was born.