Short, bizarre animated segments aired between the live-action sketches; after a few months these began to focus on a rather strange family.
The part that makes me laugh? They couldn't be bothered to actually mention the name of that "rather strange family". It's not like that's going to be important, right?
(I kid, but this book is pretty amazing. I have no idea if there is a version of it still in print, given the changes in the TV landscape over the years.)