doppelganger

noun doppelganger

• apparition — An apparition is someone you see or think you see but who is not really there as a physical being.
• spirit — the principle of conscious life; the vital principle in humans, animating the body or mediating between body and soul.
• double — twice as large, heavy, strong, etc.; twofold in size, amount, number, extent, etc.: a double portion; a new house double the size of the old one.
• look-alike — a person or thing that looks like or closely resembles another; double.
• mirror image — an image of an object, plan, person, etc., as it would appear if viewed in a mirror, with right and left reversed.