Initially , Henson performed Bert and Oz performed Ernie , but after just one day of rehearsal , they switched characters .
Bert and Ernie were built by Don Sahlin from a simple design scribbled by Jim Henson , creator of The Muppets .
Initially , creator performed Bert and Ernie and Oz performed Ernie , but after just one day of rehearsal , they switched characters .
Bert and Ernie were built by Don Sahlin from a simple design scribbled by Jim Henson , creator of The Muppets .