Doppleganger

Doppelgangers, otherwise known by themselves as Shallar, are monstrous humanoids, infamous for their shapeshifting abilities that allowed them to mimic almost any humanoid creature. Their abilitiy to become their target was near perfect, aided by their powerful telepathic abilities.
Almost extinct now, their kin, the Changeling retain a lesser version of their shapechanging power but none of the abillity to read mindds or communicate psionically.