Skiapode / Sciapode
The term Skiapode (also spelled Sciapode, Skiapod or Sciapod) derives from the Greek compound skia-podes (σκιάποδες), literally meaning "shadow-foot". Throughout history Skiapodes have appeared and again disappeared in numerous cultures and folklore traditions. They are commonly described or depicted as figures with a single obnoxious large foot, who are in the habit, as Pliny the Elder remarks, "of lying on their backs, during the time of extreme heat, and who protect themselves from the sun by the shade of their feet". 
Over the last century, much attention has been given to the topic within psychoanalysis and cognitive sciences. The philosopher and cognitive scientist Daniel Dennett for example has argued that Skiapodes must be the subject of a dreamlike 'failed myth'.  In his acclaimed lecture Dangerous Memesopen_in_new, Dennett refers to Skiapodes in relation to the Cartesian theater , and points out that "most Skiapodes hold their leg as a strange uncanny object, a thing that seems not entirely part of their body and therefore their mind." 
In one of his published cases, neuroscienist Oliver Sacks recounts the story of a patient who was so convinced one of his legs did no longer belong to him, he asked Sacks, full of disbelief and in panic: "How could this leg that is growing and getting taller by the minute possibly be mine?!"  In her correspondence with Hans Ulrich Obrist, Austrian artist Maria Lassnig (1919-2014) explains how this particular story gave rise to her famous series ‘Körperbewusstsein Bilder'. Her 1998 painting Selbst mit einem Fremdbein shows a Skiapode-like figure who feels totally estranged from her own leg ("von seinem eigenen Bein entfremdet").