Wagner, the Wehr-Wolf

Written by George W. Reynolds in 1846, this was the first book to portray a werewolf as a hero:
http://en.wikipedia.org/wiki/G._W._M._Reynolds

From the penny novel:
Wagner was a German peasant who sold his soul to the devil; in exchange, the devil transformed into a werewolf every seven years. Unusual for the period, there was a female heroine as well, Nisida, who always helped Wagner; though, she was also a murderess. Eventually, Wagner was able to free himself from this 'curse' via the Rosicrucians.

"Can it be that I have werewolf blood in my veins? After all…
Even he who is pure of heart
And says his prayers by night
May become a wolf when the wolfbane blooms
And the moon is full and bright."