Happy Caps: The long billed ridiculous looking caps that Telly tried to sell that kept smacking Elmo right in the face, knocking him down multiple times. Elmo gets so angry, he even tells Telly to call them "Dangerous Caps"
Speaking of caps, have you seen the "thinking caps" episode (late 80s/early 90s)? One of the Muppet characters (I forget who) had been sold an "alphabet thinking cap"; it made random things and people appear based on whichever letter the wearer had in mind. The letter of the day happened to be T, so our cap-wearing friend accidentally summoned a tooth-brushing Telly Monster.
Telly begged this character to take the cap back, which he did--in exchange for a "number thinking cap" that projected an image of bright-colored balls, in whichever number the wearer thought of. When this Muppet thought of 75, the resulting images were so bright and cluttered that nobody else could see. So the Street residents asked him to return the number cap as well...
By the end of the episode, this Muppet had exchanged his number thinking cap for an apparently ordinary baseball cap; but the residents were begging him not to think about anything special. He did, though--and found
himself in a baseball uniform, swinging a bat, as the final announcements played.
Drtooth said:
The Number 11: While Telly is sitting by himself in the lot (in between the apartments and Hooper's) "Also sprach Zarathustra" sounding music appears, and the number 11 pops up, like the monolith from 2001: A Space Odyssey. Telly has become obsessed with seeing this again throughout the episode. He can't get the number 11 out of his mind, to the extent of saying to Luis : "YOUR LEGS! They look like a number eleven wearing PANTS!"
Sounds like Cookie Monster's comment to Maria back in #276, in which the letter M (and Maria's legs, and everything else) reminded him of cookies.
I saw that "11 sighting" episode myself, though, and agree that it was pretty darn funny.