Fraggle Rock, on CBC (Canada) / HBO (USA)
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There was later an animated series based on this show, which I have no recollection of ever seeing. But I suppose it's possible. As for this show, I watched it on a Canadian channel, since I didn't get HBO. Anyway, it was damn cool and crazy. There was this guy named Doc who had a (muppet) dog named Sprocket, and they had a hole in their wall that led to an underground place called Fraggle Rock, where a race of muppets called Fraggles lived. Sprocket would chase any Fraggles who came out of that hole, but Doc was quite oblivious. He was some crackpot inventor or whatever.
Anyway, that's not important. The greater part of each episode took place down at Fraggle Rock. The main Fraggles were Gobo, Mokey, Wembley, Boober, and Red. There was also Gobo's Uncle Traveling Matt, who was an explorer who travelled around in the human world and sent Gobo post cards about his adventures learning about the "silly creatures" (humans) and stuff. The postcards went to Doc, who threw them out, and Gobo had to get past Sprocket to get them out of the trash. Gobo would start and finish reading the post cards, but in between, we'd see video of Matt's adventures, which he narrated.
Anyway... um... what else? Fraggles sing and dance alot. They're mostly pretty silly. They like to have fun, except for Boober. He mostly likes to be depressed and do laundry and maybe cook cabbage or something. Hmmm, Red is the craziest Fraggle. Her best friend is Mokey, who is very serious in a way, but sort of um... a mother hen... She worries about everyone. She's also sort of a hippie-holistic type, or whatever. Wembley is Gobo's best friend and not all that smart, rather frightened alot of the time. Or is he Boober's best friend? Or is Gobo Red's best friend, I dunno, it's all kinda hard to tell.
Also there are creatures called Doozers. They're always working at constructing stuff with building materials made from radishes. The Fraggles eat their constructions all the time. Radishes are grown by Gorgs, huge hairy creatures who think of the Fraggles as pests they want to catch and kill. We only see three Gorgs: The king, the queen, and their son, Junior (who is kind of a dunderhead). Also out in the Gorgs' world is a trash heap named Marjorie, who the Fraggles go to for advice. A couple of ratlike creatures work for Madame Heap, as like announcers or whatever.
Um... anyway, the Fraggles... I dunno what to say, they're all just really silly and crazy and get into trouble and have adventures and play alot and occasionally sort of learn stuff, but mostly it's about playing and singing and being silly. It's so great! (Oh, there's plenty of allegory and social commentary and stuff, you can read about that on Wikipedia, if you like. I'm not saying I didn't enjoy that aspect, but mostly I remember the fun.)