Please explain to me the funniest joke ever told by Johnny Carson

Take a look at the Google Ngram for the word “nimrod”. Notice that it peaks in 1944, drops until 1991, and peaks again at 2013. This is consistent with the 1940 Bugs Bunny cartoon causing it to become popular as an insult, then it dropped until the 1997 Green Day album Nimrod was released, then it increased again, and then it dropped again:

Bugs Bunny also originated the epithet “maroon” as a mocking jibe at his antagonist’s intelligence. It was probably a play on “moron” and not a racial slur as some have suggested. However I don’t think “maroon” ever came to be as widely used as “nimrod”. Although I’m pretty sure it inspired Maroon Cartoons in Who Framed Roger Rabbit.

Bugs called Yosemite Sam a Nimrod in “Rabbit Every Monday”

You’re right. Just watched it. All the research I had done said it was a Mandela. It’s usually reported that he said it to Elmer in A Wild Hare instead of Yosemite, but he did say it.

Is that from Bully for Bugs? I vaguely remember Bugs saying “what a maroon. What a nin-cow-poop.”. Deliberately mispronouncing the second because he was fighting a bull. Is there some way that the mispronunciation of ‘maroon’ was somehow bovine related?

Maybe, Mel Blanc misread the script and said “maroon” instead of “mooron”.

I’m sure Bugs said “what a maroon” in several cartoons. I found a few:

In Devil May Hare he says “what a maroon” in reference to the Tasmanian Devil.
In Bully for Bugs he calls the bull an “ultramaroon”.
Not sure which cartoon this is, but he says “poor little maroon” in reference to Yosemite Sam.
I’m sure he’s called Elmer Fudd a “maroon” as well, probably more than once, but I haven’t found a clip.

He also called Elmer Fudd a nimrod in at least the three cartoons “What’s Up Doc?”, “Rabbit Seasoning”, and “The Quick Draw Rabbit”, according to a search I just did.

I have all 1000 Looney Tunes and Merrie Melodies.“What’s Up Doc?” Nope, “Rabbit Seasoning” Nope, and “The Quick Draw Rabbit” no such cartoon.

I cant find the last title, but remember, titles did change.

Maybe I wasn’t clear. I watched them and Nimrod did not come up. I’ve never heard of a title changing.

Turns out I was mistaken. He calls Yosemite Sam Nimrod in Rabbit Every Monday (1951).