Actors Peter Robbins & Pamelyn Ferdin had demonstrated chemistry as the voices for Charlie Brown & Lucy Van Pelt in the Peanuts specials. To that end, CBS prevailed upon the producers of the 1968 adaptation of Chic Young's legendary comic strip, Blondie, to cast the two as the pre-teen versions of Blondie & Dagwood's children, Alexander & Cookie. Suffice to say, aside from the quick hook given to Blondie, which went half a season on its 2nd go-round, 11 years after the first series with movie & radio star Arthur Lake reprising as Dagwood, Pamelyn had the better, lasting live-action career (i.e. Lassie, Curiosity Shop), while Robbins was hardly heard from again after his Peanuts run ended.
Of course, it goes without saying that Robbins has been in the news lately, but for the wrong (legal) reasons, and that's all I have to say about that. Frank Pilato uploaded the open to Blondie.