1. The show was almost called 123 Avenue B, but it was changed due to the fact that it was a real New York City address.
2. “Sing a Song” was originally intended to be the show’s opening theme song. The Carpenters later released a cover of the song.
3. Cookie Monster predates the show by 3 years. Jim Henson originally designed an early version of the character in 1966, for a cracker commercial.
4. Roosevelt Franklin was one of the first breakthrough characters on the show. However, his character was dropped after season 7 following letters complaining of the character was a negative African-American stereotype.
5. The first Mr. Snuffleupagus design had a much more freighting and awkward appearance. His look was softened shortly after his initial appearance.
6. The rumor that Bert and Ernie are gay dates back to 1980, when Kurt Andersen questioned the duo’s sexuality in his book The Real Thing. For the record, they are not gay.
8. Originally the Muppets and humans were not intended to interact. However, this changed once producers learned that the audiences were focusing their attention on the Muppets and ignoring the actors.
9. In 1970, Ernie’s signature song “Rubber Duckie” reached No. 16 on the Billboard Hot 100.
11. Ernie wears horizontal stripes on his sweater to make him appear more relaxed; while Bert wears vertical stripes on his sweater to make him appear more uptight.
12. Oscar the Grouch was originally orange.
He changed to his trademark green color in the second season.
13. In 1990, after Jim Henson’s untimely death, Kermit the Frog disappeared from the show. He reappeared in new segments in 1998.
Also, Jim Henson never considered Kermit a regular, he always referred to him as “Sesame Street’s #1 guest star.”
14. In 1980, C-3PO and R2-D2 visited Sesame Street.
C-3PO and R2-D2 where there on a secret mission to deliver a message to Oscar the Grouch.
15. Guy Smiley’s real name is Bernie Liederkrantz.
Guy was Jim Henson’s least favorite character to perform.
16. Originally Snuffleupagus was only be seen by Big Bird. The adults on the show refused to believe he existed and thought he was just Big Bird’s imaginary friend.
This was changed in 1985 when producers felt that the adults’ refusal to believe Big Bird would discourage children from sharing important things with their parents.