This year, Emmet Otter turned 40. It aired in Canada first, for Christmas 1977, before hitting HBO the next year, and network TV 2 years later.

Here’s a nice oral history. You probably remember it fondly from your childhood, but it’s also a tour de force of groundbreaking puppet filmmaking. No, I’m not kidding:

Though filled with old-fashioned charm, Emmet Otter actually employed a savvy blend of age-old puppetry techniques and cutting-edge animatronic technology. Engineering wizard Franz “Faz” Fazakas, a frequent Muppet collaborator, designed the rowboat that could be steered along the set’s 50-foot river, and rigged versions of Ma and Emmet that could be operated via remote control while they were on the water.

Oh, also:

The tale of Frogtown Hollow continued to hold a special place in the hearts of those involved — including Henson, who included one of Emmet Otter’s songs in the musical program he designed for his memorial service [in 1990].

Paul Williams: The last thing that I ever expected was to hear “When the River Meets the Sea” at Jim’s funeral. It was an especially emotional moment in the funeral for me

(Oh, and, don’t miss the actual no-kidding blooper reel, shot during the 33 takes it took to get the “drum rolls out of the shop” shot.)