Complex sentence: Harvey Kurtzman founded the satirical "Mad" magazine in 1952; an early fan was onetime cartoonist Hugh Hefner, who founded the men's magazine "Playboy" in 1953.
Split into simpler sentences: Harvey Kurtzman founded the satirical "Mad" in 1952. An early fan was Hugh Hefner, a one-time cartoonist, who founded the men's magazine "Playboy" in 1953.