And the koosbanians.
One can argue Vincent Price, also, as he appeared on the Muppet Show. As did Moominschantz(sp,) Ray Clark, Linda Ronstadt, Harvey Korman, and Edgar Bergen.
One can argue that they are NOT muppets, because they could move about on their own, but of course, Moominschantz cannot, so... is John Cleese a muppet?
Alice Cooper, obviously, is a Muppet, as he can transform into a huge version of himself on stage.
On the internet, everyone knows you're a cat — and that's totally okay.