From Muppet Wiki

Jim Kroupa (sometimes credited as James J. Kroupa) is a puppeteer and puppet builder who has worked on several Muppet projects. He is a co-owner of 3/Design Studio, which has built puppets for shows such as Eureeka’s Castle, Between the Lions, and It's A Big, Big World.

Muppet/Henson Credits

• The Muppets Take Manhattan
• Little Muppet Monsters: Penguin(conductor)
• Sesame Street
• Sesame Street's Staying Up Late
• The Wubbulous World of Dr. Seuss: Annoying Greebles, Dad Jalloo, Doily-Cart, Mr. Wimpletwerp, Space Creature, Zippedy Quick
• Bear in the Big Blue House: Jeremiah Tortoise, Benny the Bat, Otto Otter, Ferret Jeeter, Various
• The Producers: Pigeons
• A Muppets Christmas: Letters to Santa