- “I really need you, my friends! I'm in gigantic trouble!”
- —Prince Hugo, "Sneaky Lying Cheating Giant Ninja Koopas"
After his armies are decimated by giant-sized, ninja versions of Bully, Kooky, Big Mouth and Cheatsy Koopa, Prince Hugo calls apon Mario, Luigi, Toad and Princess Toadstool to protect him in spite of their much smaller stature, fearing that he is the next target of the Koopalings.
Unfortunately, Mario and Luigi are unable to protect Prince Hugo when the Koopalings attack his castle, the two being preoccupied by the Angry Sun. After bashing their way into Prince Hugo's castle, Kooky and Cheatsy proceed to capture Prince Hugo, while Big Mouth and Bully Koopa captures Toad and Princess Toadstool.
Even as Mario and Luigi, having raccoon powers, appear, they are useless in saving Prince Hugo, Princess Toadstool and Toad, as the two are easily defeated by the gigantic Koopalings. With Mario forced to retreat atop the Royal Parrot, the Koopalings transport Prince Hugo, Princess Toadstool, Toad and the recently captured Luigi to King Koopa's Castle.
In King Koopa's throne room, Koopa inacts his plan to transform Prince Hugo into a poodle by using one of his wands. As a poodle, Prince Hugo is forced to suffer from the ridicule and mocking of King Koopa and the Koopalings and is seemingly unable to aid Mario, Princess Toadstool, Toad and Luigi in their battle against King Koopa, Cheatsy, Kooky, Bully and Big Mouth.
Eventually, after King Koopa and the Koopalings are defeated and forced to retreat from their castle, Prince Hugo is finally transformed back to normal by Princess Toadstool, by using King Koopa's wand, which had been dropped during the battle.
Having returned to normal, Prince Hugo begins to gratefully thank Mario and shakes his hand, accidentally flinging him to the ground after the spell that had made Mario gigantic was reversed by Princess Toadstool.