A couple times in Sluggy Freelance it's been pointed out that, while Riff is quick to attack Aylee, Sam, and Gwynn for being possible dangers to humanity, his own Mad Scientist experiments probably have a better chance of annihilating the human race than anything. As shown in this strip:
Riff: I hope Gwynn learned "Gwynn shouldn't mess with powers beyond her control!" (the device in his hands starts beeping) Uh-oh. You guys might want to jump up and run away, there may not be time to get a safe distance from the radioactive ... (the beeping dies down) ... never mind, it fixed itself!
Kiki the utterly scatterbrained ferret, whose specialty is Comically Missing the Point, sometimes (though rarely, because she tends to be too nice) voices the opinion that other characters, including resident schemers Dr. Schlock and Bun-bun, are "not very smart" or "get confused easily".
When Schlock, intending to blackmail the clowns at a circus where he's on security detail to get them to cut him in on their illicit brewery, discovers that his boss has already done so (since Schlock outed them several strips prior).
Security Chef Zysk: I'd fire you for it, but I'm too drunk to pronounce hippo-whatever.
And The Rant in a later strip talks, at length, about how you shouldn't judge someone on how they feel about things, but on how they act, before concluding "and if you feel differently you’re a jerk and I hate you."
"We were named by scientists, not writers or cartoonists."
Living with Insanity had an arc where Alice had to deal with customers who were rude, overly demanding and blamed her for things she couldn't control. When David takes her to a cafe after work, she does this.
At the end of the "Love and Space" arc in The Inexplicable Adventures of Bob!, Voluptua announces she will clear Galatea of all the charges against her if Bob can just get her to shut up. Zippobic chuckles ruefully in the background, as his main problem with Voluptua is her endless speechmaking.
In The Order of the Stick strip "Case In Point", Haley points out that one of the traits associated with the Lawful alignments is a willingness to enforce one's own beliefs on others. Durkon and Roy, the two most lawful members of the Order, disagree... and then tell her to stop expressing such crazy ideas.
Rival Angels sees best friends Sabrina and Sun taking in a movie after work, having snuck in their own food and booze. While waiting for the commercials and previews to end, Sabrina falls asleep and starts softly snoring. Sun turns to her and...
Owen: You're both abrasive, know-it all loudmouths who like yelling and making people wrong. Fang: *yelling* You're wrong and I'll prove it!
In Homestuck, uu expresses his hatred for the comic's tendency for long, meandering chatlogs... in the form of a long, meandering chatlog. Naturally, when this is pointed out, he shifts the blame, claiming this as an example of how "YOu PEOPLE SuCK ME INTO YOuR BuLLSHIT".
Also happens early on when Rose assures the readers of her GameFAQs walkthrough that she won't waste their time with Purple Prose...in a spectacularly overly-dramatic, purplish way.
This exchange between Jane and Dirk's auto-responder is a perfect example:
TT: Everyone needs to get into the game sooner than expected. There is a new unaccounted for variable. TT: Particularly for Roxy and Dirk. GG: What is it? TT: They are probably going to die if they don't join the game very soon. GG: Shucks!!!!! TT: Hey, I'm upset about it too, but let's watch the fucking language.
Karkat Vantas takes a turn when he spends an entire memo chewing out John and Dave for flirting with troll girls over Pesterchum...then, shortly afterward, his attempt to rip into Jade is interrupted by his own future self showing up to white knight for her, in a fashion loaded with Ship Tease.
?TG: ahahahahah oh god ?TG: dude i cant believe you were just getting on our case about hitting on the troll girls ?TG: and then literally the very next memo you are slobbering all over jade ?TG: thats just perfect hahahaha
Jake gets another, much more elaborate one later on when he sends a long, rambling monologue to Jane... all about how Dirk is too needy, has no idea how to interact with other people due to growing up on his own, and is self-centered enough to keep sending him long, rambling monologues instead of actual conversations. And he has no self-awareness whatsoever!
Katamari opens with the Prince accidentally breaking a lamp and his father lecturing him about it. This is, of course, the same King of All Cosmos who has destroyed the heavens several times.
King of All Cosmos: We cannot imagine being so reckless around something so precious.
Ramona [Dope Slaping Richard]: You're doing it again. Richard: Doing what? Ramona:Imagining things without people's permission. Richard: You do it as much as I do. Ramona: Of course I don't. I'm minutes older than you and much more mature. [in Ramona's Imagine Spot] Ramona: Now lads. You may stop fighting over your mistress. There's enough of me for everyone. Lillian: Excuse me?
In the controversial PVP Online strip, Jesus Kills, a parody of the Jack Chick tract "Dark Dungeons", a distraught Francis goes to Cole to tell him that Brent, who was expelled from their prayer for being gay, killed himself (although Francis didn't stay around long enough to see that he was mistaken). Cole then tells Francis to forget about Brent because, "Brent was a sinner. Just like all the men I'm secretly dating."