[3] After moving to WTAE-TV, Shannon became a Pittsburgh legend, particularly to the baby boom generation, as host of the popular children's television block Adventure Time.

Shannon played to a studio audience that attended each broadcast, usually scout troops, and amused his audiences with his alter ego, "Nosmo King", a play on "No Smoking" signs (but not to be confused with H. Vernon Watson (1886–1949), the British music hall artist who also performed as Nosmo King).

[1] A high point of the show came each Christmas season, when Shannon read children's letters to Santa Claus, placed them into a rocket, and launched it to the North Pole.

Shannon was one of several 1950s–1960s children's TV hosts to begin presenting reruns of the Three Stooges on Adventure Time, bringing the trio's 1930s and 1940s comedy shorts to an entirely new audience.

It helped revive the Stooges as a viable act at a time when they were considered ancient history, leading to an entirely new career of stage and film appearances.