Gumball and Darwin go with Carrie to a ghost party on Halloween night and end up undead when they drink a potion that makes them see the ghosts at Carrie's party.
- Acrophobic Bird: As ghosts, Gumball and Darwin could fly and so could Carrie, but they never try doing this when ghost hands are coming after them from the graves or when Anais is hanging off a ledge to the underworld.
- Blatant Lies:Mr. Robinson: What is going on?
Possessed moose head trophy: Nothing.
- Blunt "Yes":Gumball: Darwin! We've come too far to turn back. We're on the doorstep of the swaggiest party of all time. So come on! What do you say? You with me?
Darwin: (inhales deeply) No.
- Bowdlerise: Versions of this episode shown in Turkey and on Cartoon Network's Arabia channel cut Darwin kissing Carrie after he and Gumball are turned to ghosts.
- Color Failure: Darwin goes white from fear at the beginning of the episode, which Gumball mistakes for a costume (he doesn't wear one).
- Cue the Rain: Anais, after being hung on the tree branch by Gumball. For such a smart kid, you'd think she would know better...
- A Day in the Limelight: For Carrie.
- Dragged Off to Hell: Once Halloween ends, the ghosts go back to the underworld and because Anais, Darwin, and Gumball were ghosts at the time they start dragging them in with them. However, said ghosts accidentally take the bodies too and when the kids return to them they're kicked back into the world of the living for being mortals.
- Friendly Ghost: The ghosts at the party seem likely friendly party people, but they're anything but friendly if they think a mortal is present or another ghost is trying to stay in the mortal world past Halloween.
- Face Doodling: Darwin and Gumball draw on Larry's face to make him look like a man on a wanted poster right before Donut Cop steps in.
- Failed Attempt at Drama: Carrie tries to dramatically appear before Anais and Darwin to explain the ghosts are coming, but ends up giving her whole speech from far away while facing in the other direction. When she tries again, she gives an abridged version and Gumball beats her to the end.
- Forceful Kiss: Darwin does one on Carrie once he turns into a ghost. She blushes.
- "Freaky Friday" Flip: Gumball, Darwin, and Anais are able to get their bodies back after becoming ghosts, but they wind up with the wrong ones. As a result, Gumball becomes Darwin, Darwin becomes Anais, and Anais becomes Gumball. Carrie runs away when she's asked to help and it's never explained how this was fixed.
- Giving Them the Strip: A ghost grabs Gumball by the leg, forcing him take off his pants to get out of its grip. He tells Carrie to cover her eyes, but she can see through her own hands. After the kids are thrown out of the underworld, the pants are thrown back with them... somehow turning from spectral to solid.
- Haunted House: The ghost party is held at an abandoned house in a graveyard.
- Hit Me, Dammit!: Darwin wants someone to hit him while he's a ghost because it will just pass through... but the person he asked was also a ghost.
- I Always Wanted to Say That: After Darwin temporarily becomes a ghost, he says he can do what he always wanted to and kisses Carrie.
- Homage: When Gumball and Darwin are temporarily turned into ghosts, they try to possess Tina Rex. Their difficulties in controlling her body—having to manually operate her limbs—mirror the gameplay of QWOP.
- Idiot Ball:
- Nicole put Gumball in charge of his sibling, even though he's consistently portrayed as the least responsible. Sure enough, he uses his authority to force Darwin to go to a dangerous ghost party and leave Anais hanging out on tree branch when he couldn't be bothered to look after her.
- Anais sees the bottle of green liquid and immediately drinks some despite having no idea what it was. She apparently drank even more of it offscreen, but it's possible she did this to avoid trouble from ghosts the same way Gumball did.
- Jacob Marley Apparel: Averted when the kids' ghosts wear their regular clothing instead of the Halloween costumes they were wearing.
- Losing Your Head: One of the ghosts has no head, yet the female ghost sitting next to him can understand the sounds coming out of his neck.You're so romantic. I wish I knew where to kiss you!
- Man in a Kilt: Darwin says going through the graveyard at Halloween "Is like wearing a kilt in a hurricane—it's just a bad idea!"
- Mummies at the Dinner Table: Gumball and Darwin's bodies are left lying around when they become ghosts, and the other ghosts start dancing with them.
- One-Word Title: One of only two episodes without "The" at the start, the other being "Christmas".
- Running Gag: Carrie teleporting in but being off by some distance and facing the wrong way.
- Unwilling Suspension: Carrie and Gumball think Anais is dressed up way too cutesy for the party, so Gumball hangs her off a branch while they go inside.
- Voodoo Shark: When Carrie gives the boys a potion to be able to see the other ghosts, they start asking why they can see her.Gumball: How come we can see you every day, but we need this to see [other ghosts]?
Carrie: Duh! Because I was born a ghost!
Darwin: How does that work?
Gumball: Duh! *beat* Actually, I have no idea.
- Wallpaper Camouflage: Richard pulls a trick on some trick-or-treaters by making himself blend seamlessly into the front door and doorbell of his house to scare them off and drop their candy. His efforts are rewarded with nothing but raisins and granola bars.
- With Great Power Comes Great Perks: When Darwin and Gumball become ghosts, they uses their powers to pull a bunch of pranks and Darwin uses it to kiss Carrie.