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Nightmare Fuel: Ginger Snaps
The werewolf howls, they do not sound much like a natural wolf howl, they sound like a low long drone.
In this movie there is the idea that once you turn into a werewolf, there's no going back.
Doubled by the fact that the generally-accepted remedy for lycanthrophy, wolfsbane (although they use "monkshood" which is of the same genus) isn't a cure, it's a retardant that slows down the transformation, but ultimately doesn't stop it.
The Beast in Bailey Downs encounter, just how fast it runs and how strong it is. Just imagine, running through the dark woods, with that thing running in howling after you and it's fast enough to catch up to you.
Sam's death. Basically he was torn up a little bit, and was being kept alive by the werewolf Ginger, but was bleeding heavily. Ginger stops her attack when Brigitte shows up and she begins to give in to he developing wolf side and drink up some of Sam's blood. When Brigitte vomits it out and comes to her senses, the Ginger-Wolf bites Sam's neck, killing him.
The moment when Brigitte sees that Ginger is starting to grow a tail.
Ginger Snaps 2: Unleashed
The second movie Brigitte is on the run from a male werewolf and we don't even find out who he is, Word Of God confirms that it's not Jason from the first movie, meaning this is just some random werewolf following her around intending to mate with her.
Which, if you think about it, is more terrifying than if it actually were Jason - this means that werewolves are everywhere.
"Rocky runs, Rocky plays, Rocky misses the good old days".
During a stop at the Gas Station in the second movie, the radio plays the song Make Me Do Anything You Want by A Foot In Cold Water. The song itself isn't scary, but it gives a dark forshadowing of Ghost's plan.
Ghost's grand plan; to use Brigitte to kill people she doesn't like.