Billy (From the Balcony)

From Muppet Wiki

Billy is a male humanoid Muppet who makes an appearance in episode 17 of From the Balcony. He is built to portray a pre-adolescent male, and wears a striped shirt of unknown colors (he appears in a segment that is filmed in black & white). He talks and reacts like a stereotypical, naïve grade school child to an adult Muppet, Mr. Movie, who explains to Billy how a movie is made in the style of an educational film.

The puppet was later used in Puppet Up!