The Werewolf of Siberia

In European folklore; werewolves are humans who are able to turn a wolf at night and return to human form by day. Some change shape at will while some do not, and usually it is under the light of a full moon. What I have always found the most fascinating is how this creature by day looks just like the rest of us, but after the sun sets - they turn into a monster. And it is for that reason that a serial killer in Siberia was forever linked to this creature.