"So let me get this straight. The first girl my age I ever meet, I get a kiss like 'that'. You chase some guy halfway across the region, and not only does he reject you, but it turns out: he's gay?! Sokka: one, Katara: negative five! (Iroh: 5000)"
"Dear Zuko. Stop. Hahaha. Stop. I got a promotion. Stop. Hahaha. Stop. You're horribly disfigured. Stop. Good day."
"Oh man, can you at least roll me over so I can pretend you're fighting?" "Zip it, Zuko!"
"He's... he's blue!" "Da Ba Dee, Da Ba DIE BITCH!"
Before the battle in Episode 10:
Aang: So we're going to be flying towards the enemy. Into what you could call a zone.
Aang: And that zone is filled with danger.
Aang: So we're taking a metaphorical highway... into what could be called... a danger zone.
"When It's Done." Katara sounding like Ahnold in the Terminator (either that or Ren Hoek as the Terminator). That is all.
Katara: You heard it! I warned him! CRUSHING TIME NOW.
Aang: No, Katara, wait—!
The opening to episode 4. Kung Fu Action Jesuuuuuuuuus! He's fightin the bad guys 'n makin' 'em pay, with magic kung fu he'll save the day, it's kung fu action Jesuuuus! (cue picture of Aang's face with a Jesus beard)
"Let me get this straight. You can invent: a tank (caption: invented in 1915), a jet ski (invented in 1973) and A GIGANTIC FREAKING DRILL (20XX), but the concept of a hot air ballon (1783) eluuuuuuuuuuuuudes you."
Aang: Yeah I pretty much took care of that myself but thanks for bringing my bison. You're like a valet!
Unrelated to this series but still done by the creator is a parody of a scene fromYoung Justice, in which Blue Beetle chews out Lagoon Boy for his constant ocean puns... And then realizes he forgot to ask for the way out from the alien he was holding.