Kate Pierson Muppet

From Muppet Wiki

The Kate Pierson Muppet was the female back-up singer in the song "Furry Happy Monsters" on Sesame Street.

The real Kate Pierson is the female lead singer of the band The B-52's. She collaborated with R.E.M. on "Shiny Happy People," the song spoofed by "Furry Happy Monsters."