This one's a bit of a mystery and here's everything I know about it: In 1962, a deal was made to produce a pilot for a Marx Brothers TV show. Screen Gems, which was the television arm of Columbia Pictures, put up the dough and the show was done in what we would now call "Claymation."
Some folks have said that the animation was the work of Louis Bunin, an artist and puppeteer who made a number of films not unlike this one. I have no idea how true that may be.
Some folks have also theorized that Groucho's voice was done by Groucho himself or Dayton Allen or Pat Harrington, Jr., the latter two being comedians who occasionally replicated Groucho's voice for commercials or cartoons. I don't think it sounds like any of the three and Chico's doesn't even sound to me like a professional actor.
"Don M. Yowp" — whoever it is who hides behind that name and runs this fine, well-researched blog on Hanna-Barbera history — dug up his item from Variety for October 18, 1961…
Chico Marx, the man who never really retired, in a sense will still be "in the show," despite his sudden passing Oct. 11 in his Beverly Hills home of a heart attack, The 70-year-old comedian, eldest of the Marx Bros, and known to millions as piano-playing, Italian-dialect member of the brothers act, will appear with Groucho and Harpo as a life-like figure in an animation comedy teleseries Screen Gems is prepping.
It was Chico's third attack in the last two years, and like the others it came almost on the eve of his getting back into his "Italian" character and making with the laughs again. The figure of Chico in a special tri-cinemation—and secret—process was completed only a few weeks ago. Series will be made up largely of earlier comedy routines when the Marxes appeared together, according to studio, which will bring the Marx Bros, to fresh audiences as well as those who followed them on the Broadway stage and later in motion pictures.
Here is the video which was restored by the folks at Thunderbean Animation. It apparently did not succeed in convincing anyone back in '62 that there should be more of this…and you now know at least as much about it as I do. If you know more, share it with me and I'll share it here…