Werewolves are present in many cultures, and the name can be traced back to Old English: werwulf, “man-wolf” or occasionally lycanthrope /ˈlaɪkənˌθroʊp/ (Greek: λυκάνθρωπος lukánthrōpos, “wolf-person.” These humans have the ability to shapeshift into a wolf and back, and in the case of Logan in my book Playing with Fire, can also shift into half-man, half-wolf which provides enhanced abilities such as strength and the ability to heal quicker.
According to Greek legend, Lycaon, served Zeus a meal made from the remains of a sacrificed boy which angered him. As punishment, Zeus turned Lycaon and his sons into wolves. In Nordic folklore the Saga of the Volsungs tells the tale of a father and son who discovered wolf pelts which had the power to turn people into wolves. After donning the pelts and going on a killing spree, the father accidentally attacked and wounded his son. Luckily, he had been given a leaf with healing powers so the son survived.
Check out this article on the History Channel for some great resources if you are interested in learning more! https://buff.ly/2KjfETr