Rather than trying to top the Challenge of the Super Friends with more heroes and more diabolical villains, the 1979 incarnation of Super Friends went smaller. The World's Greatest Super Friends delivered just eight additional episodes focusing on the core team member of Superman, Batman and Robin, Wonder Woman, Aquaman, and of course the Wonder Twins. The series was paired with the Plastic Man Comedy Adventure Show beginning in September 1979. What a way to close the decade!
I don't know if the Fairy Tale of Doom episode from the previous season was a gigantic hit, or what, but World's Greatest tried to compensate for the reduced ranks by delving into the rich world of literature with many of the episodes taking the Super Friends into the far away lands of Oz and Middle Earth.
Perhaps some copyrights were infringed in the process, which is just speculation, based on the fact that while every other season of Super Friends has been released to DVD or at least to iTunes for download, World's Greatest Super Friends remains tragically unavailable for purchase.