The Raggmopps

From Muppet Wiki

The Raggmopps were a group of singing mops who performed the song "Rag Mop" in The Muppet Show episode 111. Two of the mops were later seen dancing together in that episode's "At the Dance" segment.

The act was discovered by George the Janitor, and the lead singer (performed by Peter Friedman) was the only one with a moving mouth (the stick for this mop wasn't seen).