Design a phantom-like horror creature—not a ghost, but something that exists between realms. It has a wispy, semi-corporeal form with shifting shadows for flesh, flickering in and out of visibility. Its face is a void with faint features that warp when seen directly. Long, tattered appendages trail behind it, and it emits a low, droning hum that induces dread. It stalks silently, feeding on fear and memories.