Which writer created the character Parker Pyne?

Parker Pyne is a detective who appears in Agatha Christie's anthology Parker Pyne Investigates, and the short stories "Problem at Pollensa Bay" and "The Regatta Mystery". His quote and sales pitch is always "Are you happy? If not consult Mr Parker Pyne, 17 Richmond Street." Most don't notice this ad, some chuckle, and read on. And just a few make their way to Mr Parker Pyne's modest office and meet the world's most unusual, baffling and intriguing detective.

Dame Agatha Mary Clarissa Christie, Lady Mallowan, (née Miller; 15 September 1890 – 12 January 1976) was an English writer. She is known for her 66 detective novels and 14 short story collections, particularly those revolving around her fictional detectives Hercule Poirot and Miss Marple. Christie also wrote the world's longest-running play, a murder mystery, The Mousetrap, and, under the pen name Mary Westmacott, six romances. In 1971 she was appointed a Dame Commander of the Order of the British Empire (DBE) for her contribution to literature.