The ShapeNoiser node takes a 2D Shape as an input and moves the vertices of the Shape according to Perlin noise parameters in the Controls section of the parameters.

An example of when you might use a ShapeNoiser is when carving out a city plan, you could feed a Circle Shape into the ShapeNoiser to generate a random-looking boundary to the city. The output Shape could be fed into a PlanSweep to create city walls or fed into a ShapeMerger to subtract street Shapes.