"Baby Monster" is a descriptive name used as both official and unofficial designations for various Muppet characters.
A small, pink-red monster appeared on early seasons of Sesame Street in a series of sketches with other ancillary monsters. Although he would eventually be referred to on-screen as Billy, he was named in the scripts for Episode 0168 (performed by Caroll Spinney) and Episode 0186 (performed by Fran Brill) as "Baby Monster".
In a repeated anecdote, Caroll Spinney erroneously recalls that this character would eventually become the show's break-out star, Elmo:
- The 21st chapter of his 2003 memoir The Wisdom of Big Bird addresses the topic of Elmo's rise to fame. Spinney misremembers on page 123, "the little red puppet has been around for quite a while. He debuted in one of the first seasons as Baby Monster. When the writers stopped writing scenes around the Monster Family, Baby Monster went into a storage drawer and waited there for his next script."
- When discussing using similar voices for characters with Michael Davis in the bonus interview track on the audiobook edition of Street Gang (at 11min 45sec), Spinney compares his Picklepuss character to a voice he used for Baby Monster, again mistakenly remembering it as being the puppet that would later be used for Elmo: "When Elmo — the puppet that's used for Elmo — first appeared, I was running it. He was called Baby Monster, part of a family of little monsters. I played him, and he talked with Picklepuss's voice... But that was short-lived. Eventually, he certainly became Kevin Clash who does wonderful things with Elmo."
- During a Q&A following a 2004 screening of Follow That Bird at the Brooklyn Academy of Music, someone in the audience mentioned seeing Elmo in the background during one scene in the film. Spinney said that the puppet had been around "forever" and that he'd performed him as Baby Monster in 1970 or 71, noting that the puppet was one of many AM Monsters and that lots of people had performed him.
- ABC News ran an article in 2015 purportedly boasting "7 Things You Never Knew About Sesame Street" in which Spinney again repeated a version of the story: "About the second or third year of the show, we had a series of little things we were doing called the Monster Family and I played Baby Monster, that was Elmo. They said, 'This is a cute little puppet, maybe we should make a character out of it?' and they did."
However, according to Imagination Illustrated: The Jim Henson Journal, the first design for Elmo was sketched by Caroly Wilcox in 1979, almost a decade after the events described by Spinney. Elmo's earliest known appearance was in Episode 1439 which aired in May of 1980.
An unnamed small purple monster debuted on The Ed Sullivan Show as Fred's son, who has sometimes been referred to by fans as Baby Monster. None of his known appearances address him by name, or specifically as a baby. The character was often performed by Spinney when used in segments for Sesame Street.
While Spinney's recollection of the dates don't correlate with the first sketch of Elmo, Kevin Clash mentions in his 2006 memoir that the puppet "got that name early on, though he was more commonly referred to on the set as 'baby monster'." The designation, presented lowercase and in quotes, provides a description of the puppet rather than a name. The lack of CTW documents backing up the claim would seem to conflate Clash's recollection with that of Spinney's spotty memory.
- The name runs in the family, as in the 1994 book Me Cookie!, it's revealed that before Cookie Monster got his name, he was called Baby Monster.
- One Sesame Street News Flash sketch takes place at a "Baby Monster Daycare Center". Kermit addresses each baby as "Baby Monster", though he's likely just describing each one the same, and when Kermit sees Cookie Monster in attendance and questions him being a baby monster, Cookie refers to himself as "Big Baby Monster".
- The 1975 Sesame Street song "Monster Lullaby" is sung by a mommy monster to her "baby monster".
- "New Baby" is about a baby monster.
- A Sitter for Baby Monster refers to Herry Monster's sister Flossie.
- Calvin from My Baby Brother Is a Little Monster
- Baby Max from Grover Takes Care of Baby.
- Malcolm Monster is called a "baby monster" in Where's My Blankie?
- Baby Natasha is, by definition, a baby monster.
- A character named "Baby Monster" that had multiple arms and appeared from a crib was conceived and sketched for the show Little Muppet Monsters, but ultimately went unused.
- "Fuzzyface", another instance of a mistakenly-identified early Sesame Street Muppet