What are facts about Shapeshifters?

Shapeshifters are super humans with the ability to transform into a animal or person dead, living or fictional. Shapeshifters can have the same look, thoughts and powers and abilities of the living person or fictional person and have children by impregnating human woman. Sometimes Shapeshifters have weaknesses like: being killed by silver (either by a bullet or blade, Iridium and Decapitation).