The Short Circus have a song called "We Love Chow", in which they put on fat suits and sing about how much fun they have overeating.
The skit "Spidey Meets the Yeti" where a woman's demand on Spider-Man that she will stop reading his comics if he failed to stop the title Yeti became less hilarious after the negative reception of Spider-Man comics, such as The Clone Saga and One More Day.
The Adventures of Letterman short had a villain, the Spellbinder, whose primary mission was to wreak havoc by changing letters of words into new words, causing humorous situations ... for the most part. However, there were several episodes that, while when aired in 1974-1976 might have been seen as funny, would have such situations classed as terrorism today. These include Spellbinder changing "plane" into "plant" (by changing the "e") and causing it to fall toward the earth, and removing the "b" in bridge to create a "ridge" and a way for a high-speed passenger train to fall into the crevice; both incidents put the lives of dozens of people, including children, in jeopardy. These segments would be banned from television after Sept. 11, 2001.
"Spidey Meets Silly Willy", 'No one would expect a clown to rob them!' with how ironic clowns have completely overwhelmed the unironic ones in popular culture and the 'scary clown' craze that happened, this scheme doesn't feel as plausible like it used to.
Nowadays, knowing that at least once it was Morgan Freeman in the Spider-Man suit is even funnier since in the Ultimate Marvel universe there really is a black Spider-Man.
J. Arthur Crank, especially in the first season as an offscreen character, sounds a lot like Peter Griffin.
The thought of head writer Tom Whedon penning at least some of Spider-Man's segments feels almost prophetic when recalling that his son, Joss Whedon, would grow up to write some Marvel comics and movies (nothing starring Spider-Man, unfortunately).
The Punctuation Brothers sketch begins with three grown men entering a little girl's bedroom through her window. After they give the girl a lesson in using different punctuation marks, the girl's mother finds the men in the bedroom. Instead of calling the police, she expresses thanks to the brothers for helping the girl with her homework. It's implied that the Punctuation Brothers often break into children's houses.
The Adventures of Letterman: The plane/plant and bridge/ridge segments, described above.