While Al Capp's L'il Abner never made it to television, a character from the strip ultimately did, but, oh, how Hanna-Barbera screwed up.
The New Shmoo introduced television viewers to an armless, pasty white creature who was befriended by some kids, which meant, of course, that this would end up being another Scooby-Doo copycat from the studio, as if they hadn't made enough of those already.
However, viewers were few, and NBC, panicking, decided to fuse the series together with Fred & Barney Meet The Thing, which led to Shmoo returning for a 2nd season and joining Fred Flintstone (Henry Corden) & Barney Rubble (Mel Blanc) in the Bedrock Cops shorts. H-B had also obtained a license that same season (1979) for Casper, and the results there were just as bad. Everyone was tuning in over at ABC and/or CBS, leaving NBC in the dust again.
Following is the episode, "Wail of the Banshee":
Simply put, Shmoo was not being used as expected. H-B saw something cute that kids could warm up to, but cute doesn't always translate into ratings and/or success.