Most Wolves live in the forest and living there you would think that they are vicious but they are not always like that it's just the fact that some books show wolves as ruthless killers that have no reason for the kill they make.
Example:
Little red riding hood:bad wolf
But in other books the wolves are kind and loyal
The jungle book: good wolf
Wolves are kind and loyal but they are only ruthless when you hurt their cubs because they are protective of their cubs
