From Muppet Wiki

Frankie is a cameraman for "The Alphabet Roadshow" as seen in Sesame Street Episode 4125. He shoots on location, with Fran and David Letterguy, ready at a moment's notice with his camera, for people who can recite the alphabet in an unusual way. He also appears as a stagehand in The Get Healthy Now Show.

He is a caricature of Sesame Street cameraman Frank Biondo.