Miss Simian finds Principal Brown shaved, painted, and stuffed into Gumball's locker and forces everyone to stay after until the guilty party comes forward. And things get worse when all signs point to Gumball being the likely culprit...
Tropes:
- Bookshelf Dominoes: Tobias, Anton, and Gumball slam into a bookshelf, knocking over several more, the last of which lands on Tina, as Gumball runs across the top of them.
- Bowdlerization: Versions of this episode shown on Cartoon Network Asia and Australia cut the part where Rocky pours corrosive cleaner on his hands to prove that the bald spot on his body was from a chemical burn and not from losing his Muppet fur due to age.
- Everybody Did It: By accident. Ms. Simian knocked Brown off the stairs, covering him in the paint, toilet paper, and chemicals that Penny, Rocky, and Darwin left around, then he fell into Gumball's locker.
- Enhance Button: Bobert zooms in the video of Principal Brown being knocked down the stairs and enhanced it enough to show it was Ms. Simian.
- Film Noir: Parodied in Gumball's story of Penny being the culprit, complete with shadows of Venetian blinds.
- Foreshadowing: As Ms. Simian closes the door on all the suspects, the camera hangs on the door's window, through which Bobert can be seen standing on the stairs. We later find out he was turned off and had caught what actually happened to Brown on video.
- When Gumball accuses Rocky, the spotlight accidentally falls on him instead before being moved over Rocky. At the end, after running out of suspects, Gumball is blamed for the crime and is chased by his classmates.
- Furry Reminder: Darwin exhibits extremely poor memory throughout the episode, referencing the myth that goldfish only have a three second memory.
- Given Name Reveal: This episode reveals Principal Brown's first name to be Nigel.
- Grievous Harm with a Body: Tobias throws Idaho at Gumball as a projectile.
- Laser-Guided Karma: Ms. Simian accidentally slams a door on Principal Brown and later erases Bobert's memory to get rid of the evidence of her involvement, only to get a taste of her own medicine when Principal Brown opens the door on her the same way she opened it on him, sending her flying out the window and into the path of the ambulance that came for her.
- Medium Awareness: When seeking out whom to accuse of stuffing the principal in his locker, a spotlight shines on whoever is being accused. When Gumball tries to accuse Rocky, the spotlight doesn't come on at first. Gumball then looks offscreen and says "I said it was him!"
- Medium-Shift Gag: As Principal Brown is knocked out of a window by Gumball, he's suddenly depicted as a live-action wad of hair wrapped in toilet paper.
- Not Helping Your Case: Gumball compiles all the evidence and obliviously declares himself to be the only possible suspect.
- Screw This, I'm Outta Here: Gumball, after being accused of the crime, runs from the class, prompting others to chase him.
- Shadow Discretion Shot: Penny knocking Principal Brown out with pom-poms in Gumball's theorized version of events is only shown in shadow.
- The Corpse Stops Here: Gumball is the first one suspected because Brown was in his locker, even though if Gumball put him there he clearly would have never opened it like he did.
- Tempting Fate: Principal Brown falls out the window and says he can't be in more pain right before the school bus runs over him.
- Toilet Paper Trail: Darwin had been trailing toilet paper stuck to his shoe all day without noticing.
- The Unapologetic: Despite learning that it was Ms. Simian that caused the entire thing with Principal Brown in Gumball's locker, Gumball's classmates don't even bother apologizing to Gumball for chasing him when they thought he was the culprit.
- We Need a Distraction: After Gumball is seemingly proven as the real culprit, he claims he has to go get one last piece of evidence and books it.
