A Beerwolf (Bärwolf, Werwolf, meaning bearwolf, werewolf ) is a German folk-tale monster. Beerwolf is a concept introduced by Martin Luther (in a 1539 debate) that Luther uses to describe the Pope and Holy Roman Emperor Charles V. In the context of resistance theory, a "Beerwolf", "in contrast to a mere tyrant, not only broke the law, but overturned the entire moral order upon which it is based. All the subjects of such a ruler ... had the right to resist and even to kill him and all his supporters".