From Muppet Wiki

McDonald's made a set of commemorative glasses in 1981 to promote The Great Muppet Caper. Illustrations by Daryl Cagle.

The four glasses include:

• Kermit on a bicycle
• Miss Piggy on a motorcycle, crashing through a stained glass window
• Kermit, Fozzie and Gonzo in a hot air balloon
• The Muppets on the Happiness Hotel bus

There was also a promotional glass produced that was available only to the managers of McDonald's which promoted the commemorative glasses.

Promo Poster