From Muppet Wiki
Mr. Snuffleupagus is a full-bodied Muppet character who lives with his family in a cave just off of Sesame Street. Snuffleupagus is his species as well as his last name.
His full name is Aloysius Snuffleupagus, although his friends call him Snuffy. He is eternally 4-years-old, and celebrates his birthday on August 19. Snuffy's best friend is Big Bird, whom he affectionately calls simply "Bird." His favorite foods are cabbage and spaghetti. In the fifth season premiere, he revealed that he also drinks sasafrass tea. He has a little sister named Alice and a friend named Rosalyn.
Mr. Snuffleupagus first appeared on Sesame Street in episode 0276, the third season premiere. When he first appeared, many of the adults assumed that he was Big Bird's imaginary friend, due to a series of coincidences and near-miss encounters that continually kept Snuffleupaguses and humans apart. Big Bird would often try to find ways for Snuffy to meet the adults, but something would always cause Snuffy to leave before the humans could see him. Sometimes, all it would take for the adults to see Mr. Snuffleupagus would be to turn their heads, yet they usually wouldn't do so until Snuffy had already gone.
Various kids could see Mr. Snuffleupagus, some Muppets saw him, and even a few celebrities (including Judy Collins, in a fantasy sequence) saw him, but the major human characters never believed his existence until episode 2096 in 1985.
Mr. Snuffleupagus became real to the entire cast for a few reasons. One was because the writers were running out of new ways to have Snuffy just barely miss meeting them. Another factor was increased concerns that the adults' refusal to believe Big Bird's claims of his friend's existence would discourage children from sharing important things with their parents. 
It takes two people to perform Mr. Snuffleupagus. The person who performs the front also performs the voice. Jerry Nelson was the first to play the character, but back problems caused by the physical stress of the performance forced him to bow out. Michael Earl Davis took over for three seasons (1978–1980; see Talk:Michael Earl), before Marty Robinson became the permanent voice and face of Snuffy. The back of Mr. Snuffleupagus has been performed by Richard Hunt, Brian Muehl, Frank Kane, and Peter Friedman, but since 1979, the regular back-end has been Bryant Young.
In the early years of Snuffy's Sesame Street appearances, his entrances were scored by a low-range brass musical cue. A modified version of this theme appeared on the various Sesame Street albums. Also, during his first appearances in 1971, Snuffy spoke in a sad-sounding tone of voice. Later, the sad tone was dropped and Snuffy began to speak in a more neutral tone of voice that could sometimes be cheerful. In his debut season, he also had some strange topics on the show, such as being afraid of fruit and wanting to move in with Big Bird. Also, sometimes he would answer questions with statements that did not make sense. Such as in the closing of his premier episode Big Bird asks "Where did you go?" and he replies "Well I suppose so."
For a time, his catchphrase was "Ohhh, dear." When not filming, the producers of Sesame Street hang Snuffy from the studio ceiling, wrapped in a pink blanket. They call him the Big Pink Moon. They place him there because the suit is so enormous that there is no room for him in storage.
Mr. Snuffleupagus' Family
Uncle Abe, with Big Bird and Snuffy.
Mr. Snuffleupagus lives with his family in a cave located at 456 Snuffle Circle.
In 1992, the producers of Sesame Street tested an episode in which Snuffy's parents get a divorce. After a series of arguments, Daddy Snuffle moved out of the cave, and Snuffy and Alice had to deal with the emotional fallout of a breakup. The episode didn't test well with children, and the producers decided to shelve it. In the context of the show, Mommy and Daddy Snuffleupagus are still married. For more information, see "Snuffy's Parents Get a Divorce".
Snuffy in front of the mythical Mount Ihu Papa'a Lo'ihi Nui, aka Mount Snuffleupagus.
The original Mr. Snuffleupagus and his pal Big Bird.
- The original Mr. Snuffleupagus puppet had bright yellow eyes, immobile eyelids, and yellow eyelashes. He was redesigned in Season 4, gaining white eyes, eyelids, and eyelashes, to look more like he does today.
- Sometime before seeing for themselves that he was real, Maria, Gordon, and Linda all decided to believe that he was real despite the lack of evidence, while Uncle Wally initially believed that he was real, claiming to have encountered various Snuffleupaguses over the course of his travels.
- Martin Robinson once said about Snuffy, "He's not invisible, He just has bad timing!" 
- In one episode, Snuffy tap danced with Maurice and Gregory Hines, known as the Hines Brothers, who were at that time appearing in the Broadway musical Eubie!
- His shoe size (or at least his roller skate size) is 65 triple G.
Snuffy in 1972
Maria finds Snuffy's huge toaster left at the Fix-It Shop.
Before his existence was revealed to the grown-ups on Sesame Street, there were many instances when the adults almost saw Mr. Snuffleupagus, only to just barely miss him. Some even heard him talk, but thought they were imagining things. Here are some of the many close encounters between Mr. Snuffleupagus and others.
- In Episode 0323, Big Bird takes a picture of Mr. Snuffleupagus, but when he shows the picture to the adults, they think that they're looking at an old rug and a furry rope.
- In Episode 0536, Big Bird and the adults play a game of Follow the Leader. Big Bird wants them to wait for Mr. Snuffleupagus to arrive, but they refuse to wait, thinking that otherwise they'll never play. After they start playing, Mr. Snuffleupagus shows up and takes the last place in line. David is the leader, and tells everyone to close their eyes, which causes them to miss Snuffy. Snuffy gets tired and leaves before the game is over.
- In Episode 0746, Mr. Snuffleupagus attempts to introduce himself to Mr. Hooper. Unfortunately, Mr. Hooper is wearing headphones and reading the newspaper, so he can't see or hear Snuffy. Big Bird comes in and finds Snuffy taking a nap next to Mr. Hooper, but Mr. Hooper still insists that there's no such thing as a Snuffleupagus.
- In Episode 0796, Mr. Snuffleupagus walks down Sesame Street, counting the number of people who don't see him -- including Susan, Gordon, Mr. MacIntosh, Cookie Monster (who gets his head stuck inside a bag of cookies), Bob, David, Maria, Mr. Hooper (who loses his glasses when Snuffy walks in front of him), Willy, and Luis (who holds a stack of boxes that block his vision).
- In Episode 0807, Mr. Snuffleupagus comes to Sesame Street wearing black-and-white overalls. Bob has dozed off on the stoop, and wakes up just as Snuffy is leaving. Bob gets a glimpse of Snuffy as he's waking up. However, when Bob tells Big Bird about seeing the Snuffleupagus, he mentions the black and white stripes, and Big Bird thinks Bob must have been imagining things.
- In Episode 0858, Mr. Hooper has lost his glasses again. Groping around for them, he feels Snuffy's fur, but he thinks that he's touching the furry scarf that Maria lost.
- In Episode 1186, David thinks he hears Big Bird talking to Mr. Snuffleupagus about going to the movies. He convinces the other adults to come to Big Bird's nest. When they get there, Snuffy is gone, and they decide that David must have been hearing things.
- In Episode 1800, Snuffy takes his broken toaster to the Fix-It Shop. He speaks with Maria, who's too busy to look up; she tells her customer to leave the toaster for her. When she looks up, she's amazed to find a Snuffleupagus-sized toaster. Maria shows Olivia the huge toaster, and wonders if she spoke to Mr. Snuffleupagus. Olivia thinks that Big Bird must be playing a trick. They wait to see if Snuffy comes back to pick up the toaster -- but Big Bird comes for it instead; Snuffy asked him to pick up the toaster for him.
- In Episode 1836, Forgetful Jones is manning a water station for the New York City marathon. Snuffy gets some water from Jones. When Bob comes by a moment later, Forgetful Jones forgets all about his meeting with Snuffy.
- In one segment, Big Bird decides that it's a good day for Snuffy to meet his friends. Big Bird asks Snuffy to stay at his nest area while he looks for friends, and finds David and Olivia, who have to go vote for a candidate (it's election day). Big Bird wants to learn more about voting, so they take him to the voting area and show him how things work. Big Bird then remembers that Snuffy is still waiting to meet them, and runs back to his nest area to take Snuffy there, to meet them and also learn about voting. When they get back, Olivia has already left, and David is in a voting booth, refusing to come out while he's voting. He also explains that Big Bird can't vote because in order to vote, one has to be registered and 18. Snuffy realises that his mommy is over 18, and leaves to see if she is aware that it's election day, stating that it's more important than meeting Big Bird's friends. David then comes out, having heard Snuffy's voice, but still doesn't believe that Snuffy was actualy there. He then tells Big Bird that there's another important qualification for voting, besides being over 18 and registered: "You also have to be real!" (SSvideo)
- In Don't Eat the Picutres, Snuffy walks by the museum guard, played by Paul Dooley, and mumbling to himself, but the just beforehand, the guard had removed his glasses and was now wiping them and not paying attention.
Books that focus on Snuffy include:
- ↑ Muppetbook Bio
- ↑ Borgenicht, David. Sesame Street Unpaved, p. 41.
- ↑ Personal Interview, Austin Costello