Any scene where Cao Cao escapes is guaranteed to produce some laughs, even if it turns him into the resident Butt Monkey and Crosses the Line Twice in doing so. We have, to wit:
Cao Cao's abortive first attempt to assassinate Dong Zhuo ends in an overly-contrived excuse to present the (borrowed) sword as a gift. Then he flees the scene (after Lu Bu, of all people, saw through this), kills his uncle's family in a fatal case of (literal) Chinese Whispers and finally his uncle lest he find the bodies. Distracting his uncle with "Look Over There!" sure was great practice for the next example...
Cao Cao's escape from Lu Bu's ambush: just as Cao Cao is heading towards his escape route, Lu Bu arrives on the scene... and, not recognising him at all, taps him on the helmet with his halberd and asks, "Where is Cao Cao?" Cao Cao's response? "Look Over There!" It works.
Cao Cao fleeing the Battle of Chi Bi: He gets ambushed by Lu Meng, Ling Tong, Gan Ning and Taishi Ci and Lu Xun (all of Wu), and barely manages to escape. Then he laughs at Zhou Yu and Zhuge Liang for not setting up ambushes there... and gets attacked by Zhao Yun. Following their escape, he laughs again... and when his troops docall him out on it, Zhang Fei charges them. And then, just when he thinks he's escaped for good, he does a third time... and lo and behold, Guan Yu shows up. And somehow, the Chinese proverb still goes, "Speak of Cao Cao, and he appears."
Cao Cao's defeat against Ma Chao:
They came close. Cao Cao heard one of his pursuers shout to another, "Cao Cao is he in the red dress!"
So he hastily tore off his red robe and threw it away. He also heard one say "Cao Cao is he with the long beard!"
Liu Bei's marriage to Lady Sun (Sun Quan's sister, a.k.a. Sun Shang Xiang in Dynasty Warriors and the operas). It's almost one big Reverse Funny Aneurysm when considered in today's context, from Zhuge Liang's counter-plan to save Liu Bei (from the planned capture by Sun Quan and Zhou Yu's henchmen) by publicizing the wedding (predating the paparazzi/tabloids by centuries), to Lady Sun and her entourage (practically an Amazon Brigade) scaring the crap out of Liu Bei in the nuptial chambers - and scolding the Wu generals into submission when they elope. And all this while, Sun Quan and Zhou Yu are put through the Humiliation Conga by everyone else involved (except Liu Bei, who's too nice - and a hostage for the most part). At the end when Zhou Yu is retreating after a failed final attempt to salvage the whole ordeal, the soldiers of Liu Bei stick around just to taunt him.
And for Unfortunate Names, we have "He Man, the devil who shoots across the sky" ... and gets owned in the next line by a minor character. At least it was several centuries too early to be intentional.
Mi Heng, for his sheer ability to diss Cao Cao and all of his officers in Chapter 23 (where he both enters and exits), and his final line (before he's executed) in the novel: "You are like a god in a temple: You sit still and receive sacrifice, but the lack of intelligence is pitiful."
Near the beginning, a cabal of Eunuchs dominates the court of the Han Empire. One courtier tries to have them executed as part of an attempted coup. The book comments, "The Eunuchs strongly objected to that plan."
It's less funny and more amusing, but the fact that Cao Cao, along with several other leaders and officers (but mostly Cao Cao it seems), will be given a plan by an adviser/another officer, and respond with "You say what I think", or one of the many variations of this line. (It's basically the military strategy version of Ascended Fanon or Glad I Thought of It.)
The scene where Liu Bei and his oath brothers finally manage to meet the Sleeping Dragon is hella funny due to Zhang Fei's frustration.
"What an arrogant fellow is this Master?" said he. "There is our brother waiting, while he sleeps on perfectly carelessly. I will go to the back of the place and let off a bomb and see if that will rouse him."
Cao Cao holds an archery tournament at the Bronze Bird tower, with the first prize being a silk robe, and what should have been a fine display of marksmanship gets escalated to ludicrous levels:
Cao Xiu hits the bullseye,
A disgruntled Wen Ping challenges him for the robe and hits the bullseye,
Cao Hong wants in on the action and hits the bullseye,
Zhang He hits the bullseye while shooting backwards,
Xiahou Yuan hits the bullseye while bent over backwards,