The Doozer Who Didn't is the Doozer in the middle of The Legend of the Doozer Who Didn't. A normal Doozer at birth, he enjoyed playing in the Radish Dust Glen and did well in Doozer School. But as he got older he would have periods of not wanting to do anything.
As a full grown Doozer, he suddenly decided one day that he would no longer work. He started to sing songs and make up silly games like "Filling the Helmets." But the more he didn't work, the fatter he became. Eventually he began to grow a tail and fur, and soon turned into a Fraggle.
The Doozer Who Didn't was also referenced by Cotterpin's parents in the Fraggle Rock episode "All Work and All Play."