November 9, 1980.
This is one of the funniest episodes of this show. The parody of Alice in Wonderland is pulled off with all the classic Jim Hensen bizarre style.
The Mad Hatter's tea party scene is the funniest part of this particular episode.
I used to watch "The Muppet Show" every night at 7:00 and every day as well when YTV moved it to 3:30. However, looking at the list on Epguides, it is astounding how many guest stars I don't remember. I remembered Brooke Shields of course as well as Twiggy, Jonathan Winters, Carol Burnett, Roy Rogers and Dale Evans, Johnny Cash, Lena Horn, Jean-Pierre Rampaule (I hope I'm remembering that name right), John Denver, and Chris Langham. (His episode would have featured Richard Pryer but this being 1980 Pryer was too whacked out on cocaine to do the show so Hensen pressed one of the writers into service.)
It is also remarkable the diversity of guest stars the show attracted, as the list above will attest. Everybody from George Burns to Peter Sellers to Mack Davis to Alice Cooper showed up at the Muppets' theatre.
Also, with regards to the Alice In Wonderland parody episode currently under discussion, I doubt you could get away with saying the word "hooca" on a children's or "family" show today.