There's a few segments I've read about via fan memories but haven't seen any official sources that confirm them. If they exist, I want to see them (which would prove their existience, though I don't doubt they exist).
- Ernie looks out his window and sees Mr. Snuffleupagus, but when he tells Bert, Bert thinks he's imagining Snuffleupagus and tells him what an imagination is. Then Bert looks out the window and sees Snuffy, but when he tells Ernie Ernie tells Bert what he had just told him, leaving Bert unsure whether he saw Snuffy.
- Bob goes searching for Kermit the Hermit while apparrently on safari. When he finds the hermit, he tags him and says "tag, you're it!"
- I've recently seen a thread which claims there was a segment where Maria and David play characters who end up getting married. I can't remember all of the stated details, but I think it was said that they died or something immediately after marrying.
- Somebody on the forum once mentioned that the episode that came after episode 2096 (where the adults finally saw Snuffy) involved Snuffy adjusting to making friends with them, eventually leading to Big Bird being concerned that Snuffy was spending so much time with his friends as opposed to him.
And there's a few I've seen clips of that I want to see all of, at least to know the context:
- There's a clip in the opening montage in 20 and Stil Counting where Maria and Bob (I used to think it was Luis) are at a table, apparently on a date or something, and they give shocked facial expressions. I feel like I might have seen the whole scene as a kid, but can't remember anything beyond the brief clip.
- A clip in the Big Bird montage of the same special, where Big Bird comes across a one way sign. I assume the segment teaches the concept of "One Way".
- A clip that appears during the Oscar the Grouch montage in Sesame Street's All-Star 25th Birthday: Stars and Street Forever, in which Oscar is in an oversized trash can and has oversized trash, as he sings a variation of "I Love Trash".
- A very brief clip that appears in the promo for Being Green (but like all the classic clips in that promo it doesn't appear at all in the video) where Cookie Monster screams while standing in front of Oscar's trash can. Actually I think I might know what it's from: I remember long ago somebody mentioned a segment where Cookie Monster was hungry and ended up eating Oscar's lid because it was round like a cookie, only for Oscar to get mad, until it started raining and Oscar realized that without the lid the rain would go inside his trash can. I can only speculate that that's the sketch.
- A clip that appears in Sesame Street Unpaved where Roosevelt Franklin tells his mom about a time when he couldn't spell. I've read about a season two sogn called "Roosevelt Franklin Spells His Name" and speculated that this was it, but then somebody at Muppet Wiki came across several season two guides which explained this scene in detail, which going by the description is definately a different scene, as it reportedly has Susan teaching Roosevelt how to read, and it takes place on the street and is part of the street plot in which Oscar opens his own postal service. Actually I'd like to see more Roosevelt Franklin sketches that take place outside of the classroom, particularly ones with his mother (it seems there's hardly any that didn't debut in the first season).