Eric Engelhardt was a puppeteer and puppet builder. He passed away in 2007.
The O'Neill Puppetry Conference screened a video tribute to him of some of his best works including a short 2 minute zombie film that he made in the Muppet Workshop. There were a bunch of funny stories that were discussed including a funny story when he would practice karate in the Muppet Workshop late at night when no one was around in front of a big mirror which he broke and hid and when he was making a plaster mask that got stuck to his face and he had to hammer the mask off.
The Adventures of Elmo in Grouchland: Muppet builder/designer
Muppets from Space: Muppet builder/designer
It's a Big Big World: Puppeteer
Crank Yankers: Puppeteer
The Book of Pooh: Pooh (puppetry only), Shadow character design