The Wolf Man
Writer Curt Siodmak invented the essential werewolf facts that we call take to be canonical today, such as (1) being marked by a pentagram, (2) being killable only by silver weapons, and (3) the famous four-liner …
Even a man who is pure in heart,
And says his prayers by night
May become a Wolf when the Wolfbane blooms
And the Moon is full and bright.