Both Superman and Wonder Woman made guest appearances on the show. In fact, "It's All Greek to Me" (episode 13) marked the first time that Wonder Woman appeared as an animated character.
Barry Williams and the other stars were also working on the live-action series "The Brady Bunch" while doing voice work on this animated project.
The songs "We Can Make the World a Little Brighter", "Time to Change", "Sunshine Day" and "Keep On" were originally performed on The Brady Bunch (1969) and were later used on this show.
According to the book "Creating the Filmation Generation", the three eldest "Brady kids", Barry Williams, Maureen McCormick and Christopher Knight asked for unreasonable pay rises, considering that voice actors usually got paid for providing multiple character voices per series, whereas they only provided one (and would often have very few lines per episode). Therefore, for the second season, they were replaced by Lou Scheimer's children Lane Scheimer, Erika Scheimer and Hal Sutherland's son Keith Sutherland (who was credited as David E. Smith).