In 1968, a pre-famous Jim Henson and his frequent writing partner, Jerry Juhl, collaborated on a treatment for a one-hour Thanksgiving special called “The Musical Monsters of Turkey Hollow.” The outline called for Mr. Henson’s puppets to exist in real-world environs, shot on location in and around an unspecified New England town. The title characters, “small, shaggy monsters” of extraterrestrial origin, would communicate via “a rather unique musical sound” — to be created on an electronic synthesizer by the pioneering musician Raymond Scott.

Mr. Henson designed a small gang of creatures, which were built using lifelike fur and glass eyes, for the project. That summer he took test photographs of them in the woods behind his Greenwich, Conn., farmhouse — including one in which his young daughters Lisa and Cheryl help position the puppets atop a pile of rocks.

And that’s where “The Musical Monsters of Turkey Hollow” development process appeared to end. As far as anyone can tell, Mr. Henson and Mr. Juhl never shopped the project around. In a recent phone interview from her office in Los Angeles, Lisa Henson, now 55 and chief executive of the Jim Henson Company, proffered a theory: “It’s fair to say it didn’t get made because they got absorbed in ‘Sesame Street,’ ” the landmark series that began in 1969 and made Mr. Henson and his Muppets household names.

But now, 47 years after its inception and 25 years after Mr. Henson’s death, the special is coming to television. “Jim Henson’s Turkey Hollow,” a two-hour family movie starring Mary Steenburgen, with on-screen narration by the rapper and actor Chris Bridges (better known as Ludacris), will appear on Lifetime on Nov. 21. It is the first Thanksgiving-specific special for Lifetime, which has been shaking up its programming in recent years. The real stars of the special are a quartet of new woodland monster puppets, each with a name more nonsensical than the last: Burble, Squonk, Thrinng and Zorp.