Balloon-Head Conductor
From Muppet Wiki
The Balloon-Head Conductor first appeared in Our Place for a segment involving a small orchestra of balloons that popped with the tempo of the music. The sketch ends with the conductor's head slowly deflating.
When he showed up in episode 112 of The Muppet Show, he performs a similar routine, here designated by Kermit as the "Boston Pops." This time, he finishes "The Blue Danube" by popping his own head.
Another balloon-headed Muppet, the Question, appeared in episode 115. He couldn't keep his head either.
