From the Super Mario Wiki
Jean-Claude Truchet is a character from the Donkey Kong Planet skit, La nuit des vivants-morts. He is an undead journalist who partakes in mundane activities, such as having breakfast (which consists of a severed hand with ketchup) after waking up in the morning, brushing his teeth with a wire brush and going to work. He is shown to reside with other undead citizens in a neighborhood. Being a zombie, his movements are clunky and sluggish and his speech usually resumes to groans, although he is capable of articulating sentences when conversing with his office colleagues.
He is revealed to be deathly afraid of math teachers, as he flees in terror after he encounters one in the supply room where he was headed to acquire a stapler. He then takes shelter behind a desk in another room and grabs a hammer for defense, but is soon found by the math teacher who ambushes him with other office clerks that start reciting geometry facts.