Toad and Toadette stumbled into a pumpkin field looking for a costume for Halloween. Mario has a pipe costume, Luigi has a screwdriver costume, Peach has a candy costume (which fits her), Yoshi has a Koopa Troopa costume (not to be confused with a real one, of course) Birdo has a Yoshi costume, Daisy has a lipstick costume, Rosalina has a Star costume, and Wario and Waluigi shared the same costume they created: Wario's motorcycle.
Toadette: Are you sure this is where we get our costumes?
Toad: I'm not lost, either, so this is where we'll get our costumes.
The two Toads made their way to a costume dispenser in a pumpkin-shaped building.
Toad: Huh? What's this?
Toadette: It's a pumpkin.
Toad takes the pumpkin and tried to wear it.
Toadette: [giggles] What are you doing?
Toad: [grunts as he finally puts it on] It fits perfectly!
Toadette: It does? Let me try. [grunts as she tries to put it on] Hey, it does fit perfectly!
As they began to walk to the exit, Toad notices a button that says "Press this button, or else!" He insists that Toadette would press the button, but she insists Toad to do it. And he did so. The pumpkins that Toad and Toadette have on began to glow its eyes, and began to reveal a hose and a bike pump to inflate their "suits". As the air hits the pumpkins, Toad and Toadette felt their newborn costumes stretching out like a rubber balloon. They felt a cold and tickling sensation as the air touches their skins.
Toad: [laughs] Stop! Stop it!
Toadette: [giggles] Please! No more! [laughs]
Toad's pumpkin costume ballooned out faster, while Toadette is trying to put her hands together as her costume rounds out even more. Finally, their costumes are nearly the size of the small pumpkin-shaped building in diameter.
Toad can only look at their costumes now and Toadette plays along as well.
Toad: [laughs] Look at me! I'm the Great Pumpkin!
Toadette: And I'm the Greater Pumpkinette! [laughs]
As the two Toads toy with each other's costumes, four more Pumpkins glew their eyes as they find random victims outside the Mushroom Kingdom. A wind blew a piece of tape away from the sign exposing the words "Do" and "Not". So the sign said all along: "Do not press this button, or else!" Where are the four pumpkins headed? Tune to Part 2 to find out.