Four intrepid explorers are exposed to mysterious cosmic rays on a space voyage and find themselves each with unique powers and abilities. They now use their powers for the good of all mankind against the forces of evil from our world and beyond.

Their leader is Reed Richards (Mr. Fantastic), whose knowledge sent them all on their fateful flight, and who gained the abilities of a completely malleable body. Sue Storm, Reed's wife became the self-descriptive Invisible Girl, while her brother, the youngster of the team, Johnny Storm became the Human Torch. Lastly, their spaceship pilot, Ben Grimm became the super-powerful rocks-skinned Thing. Together they are the Fantastic Four.

Featuring stories straight from Stan Lee and Jack Kirby's seminal work, this Hanna-Barbera show began on September 9 1967 and lasted for 19 half-hour installments. This particular version of the Fantastic Four was widely regarded as the best interpretation of the super-hero team, at least until the second season of The Marvel Action Hour: The Fantastic Four, which also featured stories faithful to the comics. An attempt to bring back the team to television with a new animated series in 1978 failed with the widely panned The New Fantastic Four.

Unlike every other pre-2000 Marvel Comics animated series, Disney do not own the rights to this particular show, leaving Hanna-Barbera as the current rights holders, and thus Cartoon Network's Boomerang the only place where the episodes can occasionally be seen.