Question: How could Damien's mother be a jackal? That has always thrown me for a loop and I could never understand why they'd do that unless it was for entertainment purposes. I mean, I know it's Hollywood and all but that's just too far-fetched.
Chosen answer: The idea wasn't entirely Hollywood's. The antichrist is sometimes said to be "born of a jackal. " Jackals are mentioned in the Bible, and some interpretations consider them a symbol of something that is "not of God." In the movie, it means that the kid was scary as hell, literally.
Answer: It's Satan's twisted and macabre mockery of Jesus' virgin mother.
Question: Why did Mrs. Tredoni kill Father Tom?
Answer: Mrs. Tredoni was enraged that Father Tom refused to give her communion during Mass after he had given it to Catherine, who Mrs. Tredoni calls a whore.
Why did he refuse to give her communion?
Answer: He starts to genuinely like her, hence his disgusted reaction at the sick practical joke played on her.
Manky