Are Werewolves Fact or Fiction?

Werewolves are only second to vampires in terms of their popularity

So, what actually is a werewolf?

The word werewolf is most likely to derive from two old-Saxon words, wer (meaning man) and wolf

The popular definition of werewolf is a man who transforms himself or being transformed into a wolf under the influence of full moon.

A werewolf in folklore and mythology is a person who shape shifts into a wolf, either purposely, by using magic, or after being placed under a curse

So what is it about the idea of turning into a wild animal that's so intriguing and alarming?

Do werewolf stories have any foundation in medical or scientific fact, or are they simply the product of imagination?