A Note on the front of the jacket says: This Album Contains A Blackboard And Chalk And 26 Die-Cut Letters And A Make-A-Letter Bender. The left side of the inner gatefold is the chalkboard. The right side is made into a sort-of pocket to hold the letters and make-a-letter bender (probably a pipe cleaner or similar).
Each of the names of the Muppets, and the Muppets are Trademarks of Muppets, Inc. - a Columbia Records' Licensee.