Sesame Street adults first met Mr. Snuffleupagus in 1985, ending one of the show's most famous running jokes. For years, Big Bird's adult friends never saw Snuffy because he always disappeared just before they arrived.
The gag made the adults doubt Big Bird and treat Snuffleupagus as an imaginary friend. Even when Snuffy left evidence behind or appeared around children, the grown-ups remained skeptical. By the late 1970s and early 1980s, some characters—including Buffy Sainte-Marie, Linda, Maria and Gordon—began believing Big Bird, but the main group still had not met Snuffy.
The breakthrough came in episode 2096, first broadcast on November 18, 1985, after the release of Sesame Street Presents: Follow That Bird. Big Bird arranged a meeting at his nest, and Elmo helped keep Snuffy there long enough for the adults to see him. The storyline also encouraged adults to take children's reports seriously.