This insanely crazy movie about Marco Polo Stars Desi Arnaz Jr as Marco Polo and Zero Mostel as Genghis Khan. AND it's a musical!! It is as absolutely insane as it sounds. Watch the trailer for this bloated turkey and it will rise to the top of your list.

If Desi Arnaz Jr and zero mostel aren't enough, there's a whole bit about Marco Polo inventing spaghetti with Jack Weston (yes, of Willy Wonka), and then there's the fact it was filmed at Toho Studios but is a Rankin-Bass production (live action!) It's just crazy. I'm kind of upset I'd never known about it till a few weeks ago.
But shocked this has never been featured before. Just crazy.
The whole film is on YouTube but the trailer is enough to show it's worthiness for Riffing.
https://youtu.be/NzKxOjrNpQU