I LOVE Disney pins! I've amassed a pretty good collectoin myself. As for exclusively Muppet pins, I have one of Kermit playing his banjo with a rainbow behind him, one of Gonzo, one of Kermit, one of Kermit, Piggy, and Fozzie on the Muppet*Vision 3D logo, one of MIss Piggy as Lady Liberty, one of Fozzie, one of Kermit, Piggy, Animal, Fozzie, and Gonzo that says "The Muppets," one of The Swedish Chef, one of Kermit in a Mickey Mouse hat, and my pride an joys, a Hidden Mickey pin with Kermit sitting at the M*V3D fountain playing his banjo and Waldo attached on a spring, and a "Disney Artist Choice" pin that says "The Muppets!" with Kermit leaning on it and it has a wheel in back that rotates between pictures of Piggy, Fozzie, Gonzo, Animal, Chef, Bunsen, Beaker, and Rizzo.
Along with those I have a decent amount of other Disney pins. The pins are one of my favorite parts of visiting the theme parks.