Acknowledging Mettle's status as a meme on 4chan. Twice.
Hazmat's various take-thats at Marvel Comics as a whole.
Hazmat in #10: "Today's gonna suck as much as all the others... but just a little bit harder. Because it's One More Day... with no end in sight."
In #34. "I thought they'd reopen the Academy in a day. Maybe two. But this Avengers vs. X-Men thing just keeps dragging on."
In #5, Finesse shuts down Striker's attempts to hit on her in an epic manner
"You're young, rich, attractive, powerful and entitled. All the makings of a selfish, unimaginative, and unskilled lover. I have more interesting ways to pass the time. And more interesting people to pass it with."
In #22, the X-Men visit the campus. Cyclops raises concerns over a re-programmed Sentinel that one of the students uses.
Also in #22, the issue-long Snarkto Snark Combat between Quicksilver and Magneto. Especially when Finesse quizzes Magneto about him sending assassins after Pietro and Wanda as a training exercise when they were younger.
Magneto: (whispering in Finesse's ear) They had orders not to hurt them. But don't tell him that.
In issue three, Valkyrie gives the girls The Talk and serves them mead. Tigra is not amused.
Hercules' appearance in the Avengers vs. X-Men tie-ins had two big ones, mostly for him being a Large Ham.
Posing nude for the class and everyone's reaction to it. Especially when he suggests wrestling with the strapping young lads there.
The fake-out fight leading to Hercules' monologue. It lasts the ENTIRE FIGHT!
Hercules: I am undone! O cruel fate, why have you cursed me so!
Striker: Dude, you are a horrible actor.
Hercules: Sophocles disagreed. Now silence, my monologue has just begun!
Hazmat getting prisoners to leave her alone in #4.
Grizzly: Hey, kid. You just got elected hostage. Do exactly what I say and you won't—
Hazmat: Get back in your cell. Or I'll give you cancer.