Hercule Poirot is a fictional Belgian detective created by author Agatha Christie. He is known for his meticulous attention to detail, logical reasoning, and distinctive appearance, including his trademark mustache. Poirot often solves complex murder cases using his "little grey cells," a term he uses to describe his brain. The character first appeared in the 1920 novel The Mysterious Affair at Styles and has since featured in numerous novels and short stories. Poirot has become one of Christie's most famous characters, leading to adaptations in film, television, and stage, making him a beloved figure in detective fiction.