Wacker Neuson

A Persons ass that is both:

1)Non-symmetrical (width and depth), and is chunky,lumpy and purely unappealing.
2)jiggles and shakes like jello with ease by using only the slightest step or hip/waist pop

Person 1)Hey,did you see that person's huge ass?
Person 2) Yeah,she has a real Wacker Neuson on her,that thing shakes!