The play in the show was done by the Astral Drops as opposed to the comic version and of course Hilarity Ensues. It starts with Astral!Taranee literally reading the script ("Taranee reads dramatically.."), the Dragon Dance, Astral!Will insulting Knickerbocker's clothes and the Drops and Blunk using a real water hose on the audience instead of the confetti one to Yan Lin's horror.
"She's/He's NOT my girlfriend/boyfriend!"
Any time animated series Caleb reacts to an Earth object/situation.
Caleb: What's this?
Taranee: Ice cream. You unwrap the paper and eat it.
*Caleb exits and returns a few minutes later covered in melted ice cream*
Caleb: This isn't half bad - but it made a real mess of my shoes.
In "A Service To The Community" the girls take a battered Mr. Collins that they beat up (long story) and try to think up a cover story to explain their teacher's Clothing Damage. Cornelia has a plan that involves Collins' lizard and its lunch.
Cornelia: Sprinkle him with crickets and release the lizard so he thinks that Mr. Scales ripped them up.
In "Y Is for Yield", two of the enslaved citizens of Meridian are terrifyed as a slab of stone is falling on them when Phobos saves them and says: "Don't say that I never did anything for you... NOW GET BACK TO WORK!"
Also, Elyon and Nerissa bickering inside the Seal of Nerissa, and Yan Lin and her Altermere trying to calm them and bring harmony... Only for Yan Lin to take exception at the Altermere stealing her lines.
Yan Lin: "Stepping on my lines, kid."
Altermere!Yan Lin: "Because we are in harmony."
Yan Lin: "Zip it!"
Some discussion, then Nerissa and Elyon start bickering again.
Yan Lin: "That, princess-"
Both Yan Lins in stereo: "-is not harmony."
Yan Lin to the Altermere: "Quit it!"
The first summon of Will's Astral Drop in the comic book is what inspired the cartoon version: due to Will's feelings at the time the summoning went awry, and the drop (after accidentally ruining Will's written instructions) kissed Matt, then realized she was supposed to kiss Susan, asked her advice but didn't explain well the problem (so she ended up slapping Matt in public), and when Susan told her she had a date with professor Collins she replied "Have fun". All of this was not on purpose.
Orube's introduction to life as a human on Earth does not go very smoothly, as she is unfamiliar with a lot of Earth concepts, such as money... and so, when she complains that she's hungry and Will gives her some money to buy food, she misunderstands and thinks the money is food.
Orube:'*chomp chomp chomp* They don't taste very good. ...I think I'll eat the rest of it later on.
She once asked why two of the girls' teachers were beating up each other, and Irma joked they were just saluting each other. Two minutes later she first met Matt, and greeted him with a Megaton Punch. Will was not amused.
Irma: If she gets us, we're doomed!
Orube:You are doomed! I've just done what you told me to do!
Orube: So you don't have an answer to everything, Irma!
Will: We'll enter while invisible. We've already done it, and it works.
Will:*whispering to Hay Lin* Anyway, remember me to ask the Oracle why we have wings.
Matt's grandfather's reaction at finding out his grandson has been hit (either the slap from Will's Astral Drop or Orube punching him because Irma told her it was a form of salute on Earth) is to encourage the hitter: he doesn't know why, but whatever he did he needs to be punished for it.
In the final issue of the comic the Guardians have successfully passed a series of tasks to get a new power-up (they have an increased sense each and can unite in a super-powerful being with all of their powers) and not being forced to quit. To celebrate, Yan Lin had an immense cake prepared for them (only Will could see where it ended thanks to her superpowered sight), but when the girls are about to jump on it...
Yan Lin: "Wait. Did you wash your hands?"
Will: "But... Oracle!"
Yan Lin: "Oracle, and grandma too."
As they're eating, Will gives a look at what's happening to Matt, and sees him with a girl he recently met, with Hay Lin using her superpowered hearing to confirm she was flirting with him. Cue Will deciding to show off her Improbable Aiming Skills by throwing a piece of cake at her.
The girl flirting with Matt: "When I'm with you I feel so much sweetne-"
She's hit by the cake
The flirting girl: "ARGH! Oh, really fun!
'''Matt (half-surprised and half-amused):" But... It wasn't me!