Most of the historical incidents, folk-lore or not, often dealt with hard times, when game was short or the winters were especially bad.

And of course stock was the main targets and were protected by shepherds/herders.

Don't know if they were fantasy or not.

Interestingly the "werewolf" today is depicted as an evil creature but in early German and Scandanavian culture the werewolf was a hero who turned himself into a wolf to raid and harass the enemy during invasions.

eg in the "Siegfried" legends "Sigismund" and (?) turn themselves into wolves to harass and take revenge.