Doppelganger
About
It does not replace anyone and it is not trying to. It appears as you, to the people who know you best, in places you are not - your wife sees you cross the yard while you are two days' ride away, your sergeant nods to you on the stair while you are asleep below. It does not speak or interact. It is seen, and then it is not there, and the person who saw it goes quiet. In every account that survives, the one who meets their own is dead inside the year.
Stats
Save Rolls
Traits
Special Attack
Seen: 60 ft, it appears as a creature the target knows well, doing something ordinary, in a place that creature cannot be. Save Wis Mind, fail save roll 2d6+2 psychic and the target is Weary until it can confirm that person is alive and well. Cooldown 2 rounds. Cold Grip: bludgeoning, melee 5 ft, +4 to hit, 2d6+3, and it is reluctant, and it does not like being made to.
Special Defense
Not Really Here: attacks against it while it wears a borrowed face pass through and strike nothing. It must be caught wearing its own shape - in the moment between appearances, in a mirror, or in front of a creature that has never met the person it is imitating and so gives it no face to borrow. Meets Its Own: shown a true mirror it must look, and while it is looking it can be struck normally. This is the entire fight.