The episode starts with Gumball and Darwin at an arcade. Gumball is playing an arcade game and freaks out upon reaching the final boss, but after some slapping from Darwin and the assistance of "the power of button-mashing," he wins the game. Upon being confronted by the high score menu, however, Gumball struggles to figure out what to enter as his name, with only three spaces available. Darwin suggests he should use his real name, but not knowing what it is, he decides to set out to find it, a search that ends almost immediately once Nicole reminds him back home: Zach.
On the bus ride to school the next day, Gumball and Darwin whisper "Zach" back and forth to one another, excited by the revelation. At school, Gumball—now Zach—takes his new name with stride, acting out like a stereotypical jock and annoying his classmates. Darwin expresses concern for the way that he is behaving on the walk back home, though Zach ignores him, later ditching him at a grocery store for being too much of a loser.
Darwin returns home to find Anais in a boot, having been kicked out of her room so that Zach could have his own "hang-space." (Darwin, meanwhile, is forced to sleep with Evil Turtle.) Zach also made Richard sign away his position as "man of the house," forcing him to don a dress and make-up. Darwin decides to confront Zach about it, finding him in the kitchen annoying Nicole. He holds up a mirror to Zach, making Gumball realize that Zach, as an alter-ego, was taking over him. Darwin reminds Gumball of who he really is and how he fails with style by discussing the time he failed to cross a bridge in a bucket, but Zach quickly overwrites the memory to make him a winner. Nicole decides that the only solution is to rush him to the town hall and change his legal name to Gumball before Zach takes over his entire existence.
On the drive there, Zach tries to take every possible precaution to stall their arrival, snapping the car's brakes, calling the police, and putting mouse traps in his pockets. Meanwhile, Gumball navigates his plain of memory, finding many of the events of his past to be re-written by Zach to such a severe extent that Gumball starts to fade away. The Wattersons finally reach town hall, but when tasked with signing the legal document to change his name, Gumball finds that he can no longer remember it. Right as all hope seems lost, though, Gumball discovers one final memory not yet overtaken by Zach: him and Darwin at the arcade, as it was the only time he won something. Zach tries to prevent Gumball from getting to the memory, but by the power of button-mashing, Gumball is able to get past and enter his name into the arcade machine, defeating Zach once and for all and successfully changing his name. The Wattersons rejoice and hug, after which the clerk at the town hall informs them that they could have simply performed the name change on the Internet, ending the episode.
Darwin mentions the time Gumball tried to jump an unfinished bridge on the Elmore Expressway in "The Curse," the time Tobias had beaten him in the "duel" in "The Knights," the time Gumball had kissed Darwin, believing he was kissing Penny in "The Pressure," and when Gumball purposely lost the tennis match in "The Sweaters."
"Gumball" being a nickname was previously mentioned in "The Promise."
The arcade game Gumball plays is called "Doppelgänger." This foreshadows Zach's appearance, as the term refers to a double or look-alike of a person, usually evil.
The green boot where Anais is told to live in resembles the Kuribo's Shoe from Super Mario Bros. 3.
The entire episode is similar to the Doctor Who episode "The Name of the Doctor," where the Doctor's timeline almost gets completely changed.
Zach being a real manifestation of Gumball's negative traits but worse is reminiscent of Nega Scott in the Scott Pilgrim Graphic Novels.
When Gumball is slowly fading away, it is reminiscent of Marty McFly from Back to the Future.
Gumball's collar starts popping to indicate Zach is in control, but Gumball's sweater clearly does not have a collar.
There are some errors during Gumball's flashbacks:
In the scene from "The Sweaters," Carlton and Troy's positions on the court switch with Gumball's, Carlton and Troy's tennis racquets are gone, and Darwin is not present.
In the scene from "The Fridge," Zach holds the flag, standing on a rock, but in the actual episode, the flag is on a hill. Also, Zach's paint-gun had pink paint, where Gumball's paint-gun had blue paint.
In the scene from "The Curse," Gumball is shown in his Season 1 design, but when Zach alters the memory, he is in his Season 2 design.
When Darwin mentions the scene from "The Knights" where "Tobias kicked his butt" as a part of Gumball being a loser, Tobias cheated on the duel when he threw the trash can, but Gumball won the duel, meaning that he is not a complete loser.
Similarly, when Zach changes Gumball's memory in "The Fridge," he wins the paintball tournament, which makes no sense because Gumball had already won it. It is unknown why Zach changed it if it is already part of Gumball's achievements, also meaning that Gumball is not a complete loser.
When the Wattersons are in the car, Gumball's tail is seen on his right leg.
Darwin's right sock is dark blue when Gumball is button mashing.
When Gumball and Darwin are walking home on the sidewalk, Darwin has three eyelashes instead of two. This error also occurs when he is with Carrie.
When Nicole says "By being obnoxious!" her teeth disappear.
When Darwin shakes Gumball in the city hall, the outline on his left leg breaks.
Zach claims that his name is spelled "Z-A-C" during the climax of the episode, and yet "The Neighbor" proves his name was spelled "Z-A-C-H," as that is the name Gumball uses on a clipboard.
[The episode begins with Gumball playing a video game at Funland, and he starts panicking. Darwin attempts to comfort him]
Darwin: Dude, chill out. It's only a game!
Gumball: You don't understand, man. I've never got this far before. Look how much I'm sweating. [He is shown to be sweating profusely]
Darwin: Stop it! You'll electrocute yourself! [He attempts to plug Gumball's armpits, but the sweat flow moves to other parts of his body, eventually ceasing.]
Game: Round complete!
Gumball: Oh, I can't beat the final boss man! I'm weak.
Darwin: You're not weak. You just lack upper-body strength, lower-body strength, and mental strength.
Gumball: Slap me. [Darwin slaps him] Harder. [Darwin slaps him again] Ow! Softer. [Darwin rubs Gumball's face] Okay, maybe somewhere in between. [Darwin slaps him once more]
Gumball: That was exactly right.
Darwin: Come on. You can win this by the power of… button mashing!
[Gumball hits all the buttons repeatedly very fast, making him beat the boss easily]
Game: You win!
Gumball: Dude, what's the point in learning all these combos if all you need is button mashing?
Darwin: Who cares? Top score!
Gumball: Aw, man. it's only three letters in the top score. Mm, what do I go with - "GUM" or "BAL"?
Darwin: Maybe go with the least dumb-sounding.
Gumball: You're right. Let's go with "BAL."
Darwin: No. Wait. Why don't you use your real name instead of your nickname?
Gumball: Great idea! Wait. What is it?
Darwin: What do you mean, "what is it?" What kind of guy doesn't know his own name?
Gumball: You don't know it, either, do you?
Gumball: Then this shall be my quest. I will find out that name. I will stop at nothing! I will leave no stone unturned! I will climb the highest mountain, explore every island, search every cave! I will question every man, woman and animal! Fight a bear if I have to! I'll wear shorts! I'll milk a fish! I'll shave a baby!
Darwin: Climb a rainbow!
Gumball: No, that would be ridiculous. But I will lick an owl! I will wrestle a senior citizen in jello!
[Watterson house, Gumball is still speaking]
Gumball: I'll kick a crab in the face! And I'll steal a watch from a ghost! I'll eat a beard! I'll marinate a plumber! And when they write about me in history books, they will say, "He did what had to be done to find out his real name."
Nicole: Your real name? It's Zach.
The Beginning of Zach
[Elmore School Bus]
Gumball and Darwin: Zach.
Banana Joe: Who's Zach?
Gumball: I am.
Banana Joe: Oh. [to Jamie]: Gumball's called "Zach" now.
Banana Joe: Yeah. Good point.
Gumball: Hey, coach, great game last night!
Coach: You're not on the team, Watterson. [Gumball takes the ball from her and attempts to dribble it, but ends up hitting Juke]
Gumball: Go, Elmore ducks! Whoo-o-o-o-o! [Carted away by Darwin] Hey Carrie, I think we really nailed the song last night. We're totally gonna win the battle of the bands, man.
Carrie: You're not in a band. I'm not in a band. I bet you can't even give me the name of a band.
Gumball: Psch, yeah, like… Germany.
Darwin: Whoo! [Carts Gumball away]
[At the cafeteria, Gumball skates past the tables and grabs a an apple, taking a bite of it and then tossing it away]
Banana Joe: Hey, that's my cousin! [Banana Joe's cousin cries]
[At the school courtyard, Jamie and Tina are playing basketball, until Gumball swipes the ball and attempts to shoot it into the basket, but misses and hits a car]
Gumball: Touchdown! Whoo!
[Gumball skates into the school hallway, and kicks his board, which knocks out Mr. Small]
Gumball: Watch out, world! There's a new cat in town! And he's called… [Slides across the pavement] Zach!
[The school bell rings and students start exiting the school]
Gumball: School's over already?
Darwin: Yeah, and you spent the whole day with one eyebrow raised, behaving like a horrible jerk. Are you all right?
Gumball: Oh, Zach is fine.
Darwin: Are you sure? Cause Zach is kind of digesting part of an apple kid's face right now.
Gumball: That's cause Zach does what he wants.
Darwin: Sorry, but who exactly is this Zach? I thought he'd be like Gumball but with a shorter name.
Gumball: No! Gumball's a loser. Zach is the man. Zach doesn't ask. [Takes and licks Sarah] He takes. [Sarah's head falls]
Darwin: Ugh! Dude, what are you doing?!
Gumball: Zach doesn't have to explain himself because he smells so good.
Darwin: Zach, listen to me.
Gumball: Zach doesn't listen. He hears.
Darwin: That's the same thing!
Gumball: Oh, wait. What was that? I'm afraid I can't listen you.
Gumball: Walk with me. See, Zach doesn't wait for doors to open. He punches right through them.
[Gumball punches the doors, but they open before he hits them. After a while he gets frustrated and stops]
Gumball: Metaphorically, of course. [Enters the store] See, here's another example. Zach doesn't waste his time. He goes straight to the point. [Zach starts cutting in line] Make way, losers. I'm more important than you.
Gumball: You think that'll stop Zach? Well, Zach is like water. He always finds a way.
Hank: [Zach goes through the man's clothes] Oh! Ah! Ooh!
Darwin: [Follows Zach to the front of the line] You do realize you've done all this, and you have nothing to buy, right?
Gumball: Yeah, that's why you're gonna stay here and hold my place.
Hank: Hey, kid, get in line like everyone else.
Alison: You've got three seconds to move, or I'll bingo-wing you.
Marvin: Have you got no respect?!
Hank: Get to the back of the line!
Banana Bob: I'm screaming because they are! [Throws objects at Darwin]
Darwin: Dude! Can you say sorry to these people before they get to the heavy items at the bottom of the cart?
Gumball: Zach doesn't apologize. He uses his charm. Can you pay for this, buddy? Thank you.
Darwin: All right, you lovable rogue. Hey, wait! Where are you going?
Gumball: Zach doesn't hang out with losers. He lives too fast. [Zach rapidly walks out of the store]
Darwin: No, wait!
[Darwin charges after Zach but gets bingo-winged by Alison]
Alison: I warned you.
Zach Must Go
[Back at the Watterson house, an angry Darwin slams the door shut and finds Anais popping out of a boot]
Darwin: What are you doing? What happened?
Anais: Zach. He said he needed his own "hang space," so he threw us out of the bedroom. This is where I sleep now...
Darwin: What?! What about me?
[Anais points to the turtle's lair. The turtle laughs evilly, and Darwin whimpers]
Darwin: How can Mr. Dad let this happen?
[Shows Richard dressed in a skirt with makeup and a handbag]
Richard: I'm not allowed to be called "dad" anymore. Zach made me sign away my position as man of the house. What am I now? Assistant mom? Vice mother? Man mom?
Darwin: Okay... What does Mrs. Mom think of this?
Anais: Ask her yourself.
[Darwin walks to the kitchen and sees Zach poking Nicole repeatedly]
Darwin: What's going on?
Nicole: I tried to teach him a lesson by beating him at anything he chose.
Darwin: What did he choose?
Nicole: [crying] Being obnoxious!
Gumball: Yeah, I won!
[Zach runs, hops off Darwin's head, and lands on the table]