Nat Mongioi

From Muppet Wiki

Nat Mongioi has been the set decorator on Sesame Street since the beginning of the series. Mongioi has received many Daytime Emmy Award nominations for Outstanding Achievement in Art Direction, Set Decoration and Scenic Design, and won the award in 2005.

Mongioi has also worked on The Electric Company, 3-2-1 Contact and Square One TV.