The Smiler, classified as Entity 3 in Backrooms lore, surfaces in dark corners and doorways as nothing but a single glowing smile and white eyes. Its body is never seen — the lore holds that the darkness itself is its body. The entities are acutely sensitive to light, lunging toward any flashlight or artificial source they detect.
The heart of the horror is the unseen form. The outline of the threat never resolves; only a smile and eyes hanging in the dark announce its presence. Because it charges toward light, the very illumination meant to keep you safe becomes a lure that betrays your position instead.