Shapeshifter

Shapeshifters are an ancient creature and are born when a shapeshifter mates with a human. They can shift into any peron once they get their hands on a piece of that person like some hair, blood or some skin.

They often enjoy impersonating someone then killing/torturing/tormenting family members, mating with their wives, stealing and crime in general. Basically what most scumbag humans would do if they knew they could get away with it.

Identifying one:
Appart from the slightl change in personality from the original person. They have one really obvious weakness, thanks to modern technology, their eyes will flash when seen through a camera.

How to kill it:
Can be killed just like you or me.

Other Information:
They also have access to the memories of the person they have shifted into but it is a concious act, they have to specifically want to learn something about the person to remember it.