Photo from the Jim Henson Company's website "Jim Henson's Red Book".
The Flying Zucchini Brothers, an Italian acrobat/daredevil act from The Muppet Show, appeared in the stage shows The Muppet Show On Tour and The Muppet Show On Tour: 2nd Edition.
While the Brothers are Whatnot characters, the costume head designs share a greater resemblance to the Anything Muppets of Sesame Street.