What is the name of the film where the dog is called Demon? - briefly
The movie you're referring to is "Hellboy" (2004 or 2019).
What is the name of the film where the dog is called Demon? - in detail
The film in question is "The Omen" (1976), directed by Richard Donner and produced by Harvey Bernhard. This classic horror movie centers around the story of Damien Thorn, a young boy who is revealed to be the Antichrist. In the narrative, the dog called Demon plays a significant role in the unfolding of events that surround the supernatural and terrifying revelations about Damien's true nature. The film is known for its chilling atmosphere and memorable performances, making it a standout piece in the horror genre.