To help celebrate 50 years of the children's television show, the 16 stamps will feature all your favorites from the show, including Big Bird, Bert & Ernie, Elmo, Cookie Monster and Oscar the Grouch.

The Postal Service honors Sesame Street as one of the most influential and beloved children’s television shows. For the last 50 years, it has provided educational programming and entertainment for generations of children throughout the country and around the world. The stamp art features photographs of 16 Muppets from Sesame Street:
•    Big Bird
•    Ernie
•    Bert
•    Cookie Monster
•    Rosita
•    The Coun
•    Oscar the Grouch
•    Abby Cadabby
•    Herry Monster
•    Julia
•    Guy Smil
•    Snuffleupagus
•    Elmo
•    Telly
•    Grover
•    Zoe

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 and a half years old, and celebrates his birthday on August 19. Snuffy's best friend is Big Bird, whom he affectionately calls "Bird." His favorite foods are cabbage and spaghetti. In the fifth season premiere, he revealed that he also drinks sassafras 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.