#6. Kidneys: Filtration at its finest, this magical little body part removes all the filth from your ingested liquids, and turns it into more filth. A true classic, their shape has inspired many designs, from vintage swimming pools, to beans, to hospital vomit pans. The kidneys can be a vengeful little pair, and possess a unique power that allows them to spontaneously grow actual stones when angered. Don’t piss off the kidneys.