For example: "The cute little sparrow poinged around the sidewalk looking for breadcrumbs." A sparrow hopping makes absolutely no noise, yet "poing" is exactly the noise it would make if sparrows jumping made noise.
"He lurped at her from across the bar," is another one. When we describe someone as "lurpy", there's a vivid sound to that that describes exactly that sort of… lurpy behavior.
Unomatopeia deserves to enter the vernacular.