Mortimer Matz, a New York public relations impresario who was credited with introducing the raincoat as an essential fashion accessory so that recently arrested defendants could hide their handcuffs from photographers, and who co-founded a gluttonous annual hot dog eating contest to promote Nathans of Coney Island, died on June 26 at his home in Manhattan. He was 100.

Sometimes likened to an upscale version of the unsavory press agent Sidney Falco in the 1957 film “Sweet Smell of Success,” Mr. Matz contrived his share of audacious stunts, such as the time he bought a stone and had it inscribed with hieroglyphics by a curator at the Met. A taxi driver turned it into the police as planned, and an Egyptologist from the Brooklyn Museum pronounced it unreadable. But Mr. Matz, who was representing radio station WINS at the time, revealed that the drawings roughly translated as “Everybody’s mummy listens to WINS.”