Agatha Christie is a renowned British author who wrote mystery novels and short stories. Her most famous characters are the Belgian detective Hercule Poirot and the elderly spinster Miss Jane Marple. Poirot is a brilliant detective who uses his 'little grey cells' to solve complex cases, while Marple is an amateur sleuth who relies on her intuition and knowledge of human nature to solve mysteries. Both characters have been featured in numerous books, films, and television series.