Amanda

From Muppet Wiki

Amanda was not spectacularly beautiful. Her friends would say "Amanda is not spectacularly beautiful." In order to improve her mind and social life, she bought a book on how to be beautiful. Once Amanda improved her looks, Conrad Love fell for her. It didn't last, though. Amanda would soon go back to being not spectacularly beautiful.

She appeared in the "I Feel Pretty" sketch on The Ed Sullivan Show in 1967.