This, word for word.
Second place would go to a cartoon I have on my office wall, depicting an executive bound and gagged in his chair behind his desk. The window shows it is night-time. The nameplate on the desk reads “Godot.”
Jesus Christ! I was about to go googling for that one.
The first was in National Lampoon. A guy is leading a giant rooster around on a leash. People all around them are laughing. The rooster says, “my you have a big cock; my you have a big cock. Fucking assholes, I’d like to kill them all.”
A guy runs up to his wife with a newspaper or magazine in his hand, looking all excited. His wife says, " No, Harold, I don’t care to see the turd of the century."
Most of the top drawer ones have already been posted but here are some Thurber favorites.
He caught the same disease that was killing the chestnut trees .
You lucked out; some of the early licensed products of that strip had the penguin colored in, killing the point of the comic.
Similarly (I couldn’t find this one, either): Dr. Frankenstein is stepping off the airplane and realizes he left his brain in San Francisco.
The Methodist-pastor-my-wife-used-to-work-for’s favorite: (The button says, “SMITE.”)
Gahan Wilson: Two astronauts are in a rocket which has landed somewhere. They’re looking out their viewport and see short people in funny clothes dancing around the rocket and two legs in striped socks projecting from under the rocket. Caption: “Ding dong, the witch is dead!”
Click on this link and go to the second row of cartoons, on the far right of five.
It shows a guy facing St. Peter, who calls him Mr. Phelps, and says his name isn’t on the guest list. Then he’s offered a bag of marshmallows as a “destination-appropriate” consolation prize.
I had the chance to ask the artist, Leigh Rubin, (the comic is Rubes) if he meant Fred of the Westboro Baptist Church. He didn’t say yes, or no, just said a lot of people asked him the same question.
My favorite ever? I’ll have to think about it.
Meanwhile, I first heard of this cartoon in the form of a joke–the joke, as I heard it, went approximately "two hippos are wading in a pool. One says to the other, “I keep thinking it’s Tuesday”. I thought, “pretty funny, but it’d be more natural as a cartoon. I wonder if it was, originally?”
Decades pass, the internet appears, develops, and eventually is so ubiquitous that I find myself connected to it, and it occurs to me I could possibly use this tool to see if the hippo thing were in fact a cartoon. I search, I find it, and I show it to someone, who seems to express mild amusement, but goes on to explain it in a surprising way. It revolves around a pun–“‘Twos’ day”. We see two hippos, who each make two ripples, while back on terra firma (expressed by two lines), we see two palm trees. I say, no, that’s not it, it might just as well have been Wednesday or Thursday, the humor lies in the unlikelihood that what day of week it is would matter a tittle or a jot to a couple of hippos in the middle of the jungle a million miles from anything.
But then I was unsure, and I thought I’d ask around, but now as I near posting time, I’m pretty sure I was right after all. Even so, I don’t want all my typing to go for naught, so here goes…
ApallingGael: Nah, I think your friend is over-thinking it. The cartoon is nothing more than absurdism. How would a hippo know what day of the week it is? (Or care?) Still, points to him for perception and problem-solving skills. Some jokes are complex in that kind of way.
A Kliban panel: two robbers are in a bank surrounded by about fifty cops, all with their guns drawn and pointing at the robbers. One robber says to the other, “Switch to Plan B.”
A great one for those of us skeptical of advertising
And a New Yorker from 25+ years ago, I used to have the original on my kitchen corkboard
This is an old favorite http://imgc.allpostersimages.com/images/P-473-488-90/65/6595/45T2100Z/posters/benita-epstein-two-dogs-in-different-apartment-windows-barking-at-each-other-you-shut-u-new-yorker-cartoon.jpg
This is another favorite that comes to mind
Anyone who loves The Far Side will also love Doctor Fun, an early webcomic. Both comics have a heavy focus on science-themed humour, though Doctor Fun’s was often a bit more obscure. My favourite is “Don Knuth finally sells out.”
S. Harris is also known for some great science cartoons. My favourite of his is “Boole orders lunch.”.
It’s nothing more than saying there’s nothing in a hippo’s life to distinguish one day from another: wading, eating, crapping, sleeping. And after around 1 billion heartbeats, they die.
For sure, from my NatLamp reading days. 
She is all over the New Yorker these days.
mmm
There were so many good ones by Charles Addams. The Addams Family standing on top of their house preparing to tip a pot of boiling oil down onto a bunch of Christmas carollers is dear to my heart…There’s one with some zoo employees all lined up, holding an enormous python (posing for a picture of The World’s Longest Snake?), and one of them is standing to the side alone, depressed. The caption: (something like) ‘Cheer up, Higgins, you’ll be in the picture next year!’ (after the snake has grown even longer).