Continuity mistake: Season 1, Episode 5: "The Other Cousin." When Bleh enters her bus home, she receives 50 bucks from a retarded version of Spanky; there she wears her usual brown coat. But as she holds up the bill, she already wears the white fur coat she buys in the NEXT scene.
Continuity mistake: Season 1, Episode 5: "The Other Cousin". When Ling-Ling attacks the fake three-headed monster, it looks real; when Xandir, Wooldoor and Toot reveal themselves, the costume is a patchwork piece; and when they gather around a disappointed Ling-Ling, it looks real again.
Continuity mistake: When Clara's cousin takes her robe off, as Captain Hero and Spanky are going to egg her, look at her feet. One of them has six toes. The next time we see the foot, it has five toes.
Answer: You might think it has something to do with licensing rights for the characters. But that's doubtful as several of the characters, both seen and unseen, are from the same animation company, Hanna-Barbera. Actually, it's a play on the real-life reality TV show convention of blurring/obstructing the faces of people who haven't legally consented to having their image shown, because their appearance on camera would put them in a compromising position. This happens often in shows like "The Real World, " "Cheaters, " and "COPS." In "Drawn Together, " Snagglepuss and Elmer Fudd, for example, were jokingly portrayed as not giving consent to their image on TV because it would out them as gay in the context of that episode. Of course, to the viewer, it's obvious who they are, and the humor lies in our memory of them as possessing a lot of stereotypically "gay" characteristics. Charlie Brown's face was obstructed by a leather BDSM mask, part of his "costume, " in a scene where Foxxy was his dominatrix. In the same scene, Natasha Fatale has Captain Hero in a similarly submissive role wearing a spiked collar and leash. Her eyes have a black bar across them, again, so as to "conceal" her identity, the way they do in the fashion magazines, even though we the audience know exactly who she is. The other characters you mention apparently "gave their consent" to their image being shown.
Michael Albert