4. Troll 2 (1990)
The Horror: A family unwisely visits the town of Nilbog, where it is pursued by a brood of vegetarian goblins. Tsk, clue's in the name.
Most Shocking Mistake: Forget the misnomer title, the fact the director couldn't speak English or "Oh my God," the acting… and stick to the premise. In order to eat the humans, the goblins plan to turn them into plants first.
How To Make It Scary: There's absolutely no reason, beyond anti-veggie propaganda, why the goblins shouldn't be carnivores.