Metaphors referring to ducks

literary fairy tale by Hans Christian Andersen

elected official who is about to leave office

making sure a classifier is based on observables instead of expediency or arbitrariness

debugging method, in which a programmer explains code, line-by-line, to an inanimate object ("rubber duck") or to another person, until the incongruity between what the code should do and actually does becomes apparent

style of dynamic, structural typing with lazy checking of objects' attributes

alt=|thumb|Rock 'N' Roll singer Chuck Berry doing a one-legged hop style "duckwalk" while playing the guitar. The duckwalk is a form of dance performed by assuming a low partial squatting position and walking forwards, maintaining the low stance. It is similar to stalking and prowling. It is most widely known as a stage element of guitar showmanship popularized by rock and roll guitarist Chuck Berry. It is also a physical exercise commonly used in military training.

an argument showing that classification is not really possible without some sort of bias