A strong candidate for this title would be a stone cross dubbed the "Wolfstone" on a grave in the Fichtel Mountains of Germany. In the 18th century, a local shepherd hired a hunter to kill a strange, huge wolf which had been devouring lambs in his flock.
But, when the marksman took aim and fired at the predator, the bullets had no apparent effect although at least one hit the creature straight on.
However, the next day, the shepherd observed that an old woman, long suspected of practicing witchcraft in the area, was hobbling down the street, as though wounded. He deduced that she was a female werewolf, transmogrifying herself into a large wolf at night to attack his sheep.
So, he reported her to the local authorities who arrested her and chained her to the floor of a dingy cell. But, when they went to interrogate her the next day, she had mysteriously vanished.
Two nights later, while the shepherd was out in the woods with the huntsman searching for her, the killer wolf, who had been lying in wait, sprung at them!
Fortunately, the hunter had a silver knife with which he was able to slash the beast. As soon as its blood began to flow, the wolf, writhing on the ground in intense agony, morphed into human form, namely, that of the old witch, absolute proof that she indeed had been a female werewolf!
They buried her an unprecedented 20 feet beneath the ground and marked her grave with the Wolfstone cross in hopes of sanctifying it.
But, to this day, locals claim that eerie phenomena, such as enigmatic lights, are seen near that accursed site!
Ruehl Fact: Nina Foch starred as a female lycanthrope who inherited her affliction from her gypsy mother in the horror film, Cry of the Werewolf (1944).
My video account of the Wolfstone Marker:
Werewolves Are For Real:
Ancient Werewolf Accounts:
For additional fascinating information on lycanthropes and their strange cousins,I strongly commend you to Brad Steiger's "The Werewolf Book:The Encyclopedia of Shape-shifting Beings." Without a doubt,it is the most comprehensive work yet published on such strange entities,covering everything from ancient accounts to cinematic treatments of them!
Follow Dr. Franklin Ruehl, Ph.D. on Twitter: www.twitter.com/drruehl
Outside of that, I think they only exist as old folk tales and in Hollywood movies.