Gumball/Zach: Watch out, world! There's a new cat in town! And he's called… Zach!
Gumball discovers his real name (Zach) and begins developing the pushy, narcissistic attitude of someone with that name, but the family discovers that the change in personality is really Gumball's Zach side trying to take over.
Tropes:
- Absurdly Ineffective Barricade: The police put a blockade to stop the Wattersons' car because it was reported to be stolen, but it fails because the blockade went along the car's path instead of in front of it. The cruisers in the blockade put up a spike strip, which they promptly run over to chase after the car. Not too long after, Officer Donut crashes into one of the cars on the strip.
- Anti-Climax: Gumball gives a speech declaring that he'll do basically anything to discover his true name. Nicole just casually reveals it to him with no fuss involved.
- Bait-and-Switch: Gumball makes a very long list of (ridiculous) things he'll do to find his name, as if that's what the episode would be about, but then his mother tells him what it is the second she hears he wants to know.
- Bittersweet Ending: More towards sweet; the family manages to save Gumball's mind from being taken over by changing his name back to normal. However the clerk mentions that they could've done that process online, rendering their entire journey meaningless.
- Bookends: The plot is kicked off and ultimately resolved thanks to Gumball trying to enter in his name after beating an arcade game.
- Carnivore Confusion: Zach takes a bite from an apple on the table in front of Banana Joe. He responds, "Hey, that's my cousin!" and the apple starts crying.Darwin: Are you all right?
Zach: Oh, Zach is fine.
Darwin: Are you sure? 'Cause Zach is kind of digesting part of an apple kid's face right now. - Cats Are Mean: Zach is much more arrogant and assholish than Gumball.
- Chekhov's Gun: The opening scene at the arcade. Saying "Gumball" out loud makes the original personality remember his own name when the memory comes up later.
- Chekhov's Skill: Gumball realizes in the first scene that Button Mashing works better in a game than any of the combos. Gumball remembers this later, finally giving him something he's better at that Zach while Fighting Down Memory Lane.
- Continuity Cavalcade: Gumball's family try to get him to remember who he is, causing several flashbacks and mentions of previous episodes, then a trip through Gumball's memories all of which are scenes previously shown to the audience.
- Darwin reminds Gumball of the end of "The Curse", when Gumball tried to make it over the gap in the highway but failed, which Zach alters to making it while doing a hand-stand on the bucket.
- Our first view of the inside of Gumball's mind is a single pan showing an amalgamation of many scenes into one location: walking through the Forest of Doom from "The Picnic", Anais hanging from the tree branch from "Halloween", the failed delivery to the Pepperonis in "The Job", Idaho standing in front of his family at the end of "The Bumpkin", Jackie Wilson tied up in a chair from "The Sidekick", the Stomach Destroyer Gumball rode with Darwin in and the farewell bus Gumball left in while Disguised in Drag during "The Dress", Molly's treehouse from "The Pressure", the vending machine Gumball remembered being stuck in from "The Authority", Richard's punched swollen face in "The Finale", Darwin and Gumball repairing the damaged roof in "The Phone", Mr. Fitzgerald nearly hitting Penny with his car and crashing into the Watterson house in "The Knights", and the fight between Hector and Kenneth in "The Finale".
- The camera then zooms out to show a cardboard cross-section of a brain covered in video clips of previous episodes, including "The Picnic", "The Fridge", "Christmas", two from "The Finale", "Halloween", two from "The Job", "The Knights", and "The Skull".
- Darwin reminds Gumball of when Tobias fought him in "The Knight", pounding with a broom while Gumball defended himself with a trash can. Zach alters it so he brought a bazooka.
- Darwin brings up when Gumball and he deliberately lost the tennis match in "The Sweaters" because he didn't care, but Zach remember covering Troy and Carlton with a barrage of tennis balls.
- Darwin recalls his and Gumball's Accidental Kiss in "The Pressure", apparently having found out what really happened sometime since then. Both agree it'd be fine if he couldn't remember that.
- The last memory Zach is shown altering is the paintball game in "The Fridge", which he changes from winning by luck to beating everyone else hands-down.
- Continuity Nod: The turtle's pen has the Kupok the barbarian doll from "The Plan" inside of it.
- Cutting the Knot:
- Gumball does this by accident: when trying to find his real name, his mother overhears him talking about it and tells him immediately.
- The Paper Woman tries telling the Wattersons that they could have just changed Gumball's named using the Internet, but the episode ends as she says this. However, given how Zach kept sabotaging their trip to Town Hall, it's probably a given he would've taken care of that.
- Death of Personality: Gumball starts to fade away as Zach replaces more of his memories. He even momentarily forgets the name he's gone by for most of his life. Instead, Zach ends up dying.
- Distinction Without a Difference: Two instances:Gumball/Zach: Zach doesn't listen... he hears.
Darwin: That's the same thing!
Gumball: Wait, what was that? I'm afraid I can't listen you.Gumball: I can't do it! I'm weak!
Darwin: You're not weak! You just lack upper body strength, lower body strength, and mental strength! - Does This Remind You of Anything?: It comes off like Gumball has Dissociative Identity Disorder, with Zach being an alter who wants to take over because he thinks Gumball is too much a loser, and the more he appears the more exhausted and faded Gumball gets.
- Dragged into Drag: Richard is forced to dress in a skirt and wear makeup after Zach makes him "sign away [his] position as man of the house".
- Exiled to the Couch: Zach kicks his siblings out of their shared room, making Anais sleep in a boot and Darwin sleep in the turtle's terrarium.
- Flashback with the Other Darrin: All of the flashbacks featuring Gumball from season one and two episodes have Jacob Hopkins as the voice of Gumball rather than Logan Grove.
- Forceful Kiss: Zach grabs Sarah and looks like he's about to kiss her (though she's clearly willing to accept it), but instead he just licks her face because her head is made of ice cream.
- Foreshadowing: The arcade game that kicked off the episode's plot is called Doppelgänger.
- Furry Reminder: Before jumping out of the school and onto the sidewalk to strike a pose, Zach calls himself a cat.
- Get A Hold Of Yourself Man: Gumball asks Darwin to slap him to get him ready to play a video game, but makes Darwin retry several times so he's not doing it too hard or too soft.
- Instant Convertible: The Wattersons' car gets the top torn off when they run under a semi because Zach cut the brakes.
- Ironic Echo: Upon getting the arcade high score, Gumball asks "What’s the point in learning all these combos if all you need is button mashing?" During Gumball and Zach's final confrontation, Zach claims to know all the combos, to which Gumball responds "But the combos are useless against BUTT-ON MASH-ING!"
- Killing Your Alternate Self: Gumball and Zach end up Fighting Down Memory Lane over who gets to keep their body. Gumball wins, and Zach is obliterated.
- Lovable Rogue: Darwin refers to Zach as this.
- Mundane Solution: Played With. The Watterson's plan to get rid of Zach is to get Gumball to Town Hall and legally change his name. However, by the time they get there and Gumball regains consciousness to do so, Zach was already defeated thanks to Gumball's memory of the arcade.
- Name Amnesia: Gumball has been Only Known by Their Nickname so long, he doesn't remember his birth name until his mom tells him it.
- Self-Serving Memory: Zach attempts to erase Gumball from existence by turning memories of his greatest failures into victories, starting with his Near-Death Experience in "The Curse" and him getting beaten up by Tobias in "The Knights".
- Shout-Out: When Zach hits Mr. Small in the head with a skateboard, Small falls over into the same pose Peter Griffin pulled when he fell down the stairs.
- Squirrels in My Pants: Zach cuts past Hank in line when he blocks the way by crawling through his clothes.Zach: You think that’ll stop Zach? Well, Zach is like water. He always finds a way.
- That Man Is Dead:Darwin: Sorry, but who exactly is this "Zach"? I thought he'd be like Gumball, but with a shorter name.
Zach: Nooo! Gumball's a loser. Zach is the man. - Third Law of Gender-Bending: Richard even having to dress like a woman makes him act like a ridiculously-stereotypical Hysterical Woman.Richard: What? I'm stress-eating! You're not the only one who gets hormonal!
Nicole: Are you sure you don't want to take off that wig? I think it's messing with your head.
Richard: Oh, first I'm fat, and then you don't like my hair?! My mother was right!
