Back in 1975, Marvel was continuing to venture out in other media, having already launched cartoon shows of their popular characters and releasing licensed toys, etc. One such venture was the Fantastic Four radio show, premiering in 1975 and syndicated across the continent. Radio shows were still around in various forms through the 70’s into the 80’s (the original Star Wars trilogy was famously made into radio plays when the movies were released). the Fantactic Four radio shows were adaptations of the early Lee/Kirby run, with scripts lifted almost verbatim from the comics, featuring The Fantastic Four, Doctor Doom, Ant Man, Namor, Fury, Hulk, Mole Man, even Super Skrull and with Stan Lee narrating scenes. Most notable is the appearance of Bill Murray, before he became a star, as Johnny Storm. You can check out all 10 episodes at the link provided up top. Great listening at work!