Alphabet Bates is a skywriter on Sesame Street who, although rarely appearing in person, made his mark with the giant letters he made in the sky over Sesame Street. The actual skywriting in the segments was done by Cecil Coffrin of Sky Advertising Corporation.
Mr. Bates' work appeared on Sesame Street beginning in the first season. His name was mentioned in Episode 0115 when Gordon and Jay used a telescope to watch him write an E. Subsequent early mentions included Episode 0261 when Oscar and the kids watched the same letter, and in Episode 0300, when Susan spotted him making a Q. He was also mentioned by David in Episode 0536, during a game of "follow the leader".
Beginning in season 11 of the show, he began to make the occasional appearance out of the skies and on the street, portrayed by Muppet performer Brian Muehl. In these appearances, he would drop from the sky and write on-screen (with the use of a telestrator) while imitating the sounds of his airplane, then somehow rising back up into the sky. Muehl's performance had him speaking in incoherent, French-like nonsense. In season 12, he was joined by Dominique, an Anything Muppet who served as his driver (using a motorcycle).
Alphabet Bates made an illustrated appearance in the 1983 book Everyone Makes Mistakes. He appears in the animated adaption of the story for Three Sesame Street Stories, also giving him a French accent.