Fountain of Knowledge

I don't think you overdo it at all, Laura. What I mean when I say "overdo" is, let's say the ghoulish villain in your story slowly and carefully dismembers its victims and eats them piece by piece in the crypt in the neighborhood church's graveyard. If there are 15 victims in your story, you don't necessarily need to detail every agonizing nibble the creature takes from each one. Even one full description of this monstrous act is enough; the other fourteen, or at least twelve of them, could end after a terrifying pursuit, when the ghoul pounces on his hopelessly trapped supper. At that point, the suspense is over, and it becomes gore for the sake of gore. I think to describe every agonizing detail of every assault would be acceptable ONLY if there were a good reason for it (say, it's a mystery-horror-suspense story and each murder contains a different clue to the creature's evolving modus operendum, which will eventually lead to its capture), but if the only reason is to instill horror, the repetition cheapens the act, and you, the author, risk repeating the same things word for word over and over again.