Werewolves in early modern Europe didn’t just change shape from man to wolf, they also changed their shape in the popular imagination from place to place and time to time.
Being a werewolf might involve battles on the astral plane, it might involve a drunken trick-or-treating spree, or it might indeed involve turning into a monster and eating some people.
There was a lot of debate in the period about whether people ‘really’ could turn into werewolves, or whether those who claimed to do were in fact deluded, as Michael Lynn has written about.
Some authors of the time tried to square the circle by arguing that werewolves only appeared to turn into wolves – rather than really doing so. Either way, some of these people committed real crimes including murder, like Jean Grenier in France or ‘Peter Stubbe’ in Germany; some of them were sent to medical facilities instead of being executed.