Hercule Poirot (UK: , US: ) is a fictional Belgian detective created by the English writer Agatha Christie. Poirot is Christie's most famous and longest-running character, appearing in 33 novels, two plays (Black Coffee and Alibi) and 51 short stories published between 1920 and 1975. Poirot is noted for his distinctive appearance, including his waxed moustache and fastidious dress, as well as for his reliance on logic, psychology, and what he terms his “little grey cells” to solve cases. The character’s biography is developed gradually across Christie’s works.
https://en.wikipedia.org/wiki/Hercule_Poirot