I'm looking for a short educational film or films that I saw in the early 1980s. (I think that I saw two separate films featuring the same main character, but I am not absolutely certain.) They featured the animated adventures of a costumed superhero character; I remember him as having an outfit with grays and other dark colors, like Batman of Black Bolt.
The movies had very simple morals, of which I only remember one, which was about not talking to or taking candy from strangers. Somehow, the protagonist ends up on another planet where there are a bunch of creepy adults (not initially seen, as they are all in their cars) who treat him as a child. There is then some expository narrative explaining that people on this planet average about ten feet tall, complete with a lineup-type shot with the protagonist (at about six feet) shown next to a much taller alien adult. Since he is diminutive by the planet's standards, he is taken for a child.
That's all I remember. I am pretty sure that I saw this in school around 1982 to 1984. It would probably have been shown on a film projector, since I do not think my elementary school at that time even had a VCR.