similar to a dingleberry, an assfunkel is a slang term referring to vestigial remnants of feces attached to the ass, butt hole hair, and/or butt crack. They are often the result of not wiping well enough after crapping or not wiping at all. In most western cultures asselfunkels are considered a symbol of poor hygiene and are in bad taste....very bad taste.
Bob: Hey Tom, what's that on your ass? did you sit on a box of raisins or something?
Tom: Ooops! It's just a cluster of asselfunkels! Got any toilet paper?