When Fanboy introduces Yo to the concept of Prank Day, she becomes prank-obsessed and ends up pranking him nonstop; thus he and Chum Chum must find a way to get back at her.
Tropes:
- April Fools' Day: Prank Day seems to be a parody of this.
- Aside Glance: Kyle does one after Fanboy asks him to pull his finger.
- Bears Are Bad News: A bear is used a lot during the Fanlair scene at the beginning.
- Bottle Episode: The only backgrounds are the Fanlair, school, and finally the Frosty Mart, with the latter half of the episode only set there.
- Call-Back: Fanboy gets Kyle to pull his finger, releasing fart from his head. This is an inverse of "Wizboy", where Kyle refuses to pull Fanboy's finger but gets farted anyway.
- Enemy Mine: Fanboy and Chum Chum work with Boog to prank Yo.
- Idiosyncratic Wipes: Yo's sticker provides the transition in the style of 50's Batman.
- Pie in the Face: Happens a lot.
- Pranking Montage: Yo getting hooked on pranks and humiliating Fanboy nonstop, complete with the "In Yo face" sticker and catchphrase.
- Running Gag: "In Yo Face!"
- Tastes Like Purple: This is literally said by Chum Chum after he tastes some trick gum, turning his teeth purple.
- Unsportsmanlike Gloating: Fanboy, Chum Chum, and Boog all dance around while chanting "How you like us now?!" near the end, after finally pranking Yo.
- What Happened to the Mouse?: Kyle is not seen again after being pranked. Yo takes over for the rest of the episode.
