The episode begins with a bubble with a letter inside flying to SpongeBob's house while causing mischievous antics. It finally flies into SpongeBob's kitchen, who is enjoying a bowl of Kelpo cereal with Gary. SpongeBob opens the letter, which is from his old friend, Bubble Buddy, asking him to babysit his son, Shiny. Shiny appears out of the bubble holding the letter. SpongeBob introduces himself and takes Shiny to meet Squidward. Unfortunately, Shiny caused mayhem in Squidward's house and SpongeBob couldn't find him. Shiny kept flying again in Squidward's house and destroying furniture.
Eventually, SpongeBob catches him and takes Shiny to The Krusty Krab. Then, he went into Mr. Krabs's office and flew everywhere around him. Mr. Krabs was shiny and clean from the bubble soap and told SpongeBob to let Shiny play in the dirty dishes. Then, while SpongeBob was cooking Krabby Patties, Shiny once again gets into mischief by sliding around, making the Krusty Krab floors slippery. All the customers kept slipping, so Mr. Krabs kicked them out. Then, Shiny flew into the city and got into lots of trouble.
He went into the pin factory, the scissor works, and he went into the pitchfork pantry. Then, SpongeBob decided to go to the pillow foundry and he found out that was a dangerous place too. When they got home, he fed Shiny a hot dog. But then he popped, and SpongeBob had the bubble soap to repair him. Finally, when he blew another Shiny, he grew two heads. Then, Bubble Buddy came to his house to pick up Shiny. SpongeBob begins to apologize about Shiny, but Bubble Buddy says that it was okay, because sometimes, it had happened to Shiny. Then, he traps Shiny into a bottle of bubble soap. As they were leaving on a plane, Shiny is normal again, blowing a raspberry out from the bottle and they went into the plane and flew away.
The bubble plane was first on the ground, but was lifted into the sky. The same thing happens to the taxi at the end of the episode "Bubble Buddy."
Shiny showed no signs of life until the end, just like his father in "Bubble Buddy."
In the letter from Bubble Buddy, it says "We don't want him to go pop like his late Uncle Raymond". This is the first mention of any relatives of Bubble Buddy. It's possible that Raymond is Shiny's maternal uncle because SpongeBob might not remember creating Raymond from bubble blowing.
Squidward painted his self-portrait to resemble Napoleon Bonaparte.
Mr. Krabs makes reference to Bubble Buddy's visit in Bubble Buddy and him not paying.
As seen in other episodes, bubbles in the SpongeBob SquarePants universe have properties more similar to inflated balloons than bubbles. For example, when Shiny was caught in the blades of Squidward's fan, he wasn't popped. Instead, he spun around them, the way a helium-filled balloon would if caught in the same situation.
Figuratively speaking, Shiny is SpongeBob's grandson because SpongeBob created Bubble Buddy and Shiny is Bubble Buddy's son.
Running Gag: Shiny floating into different sharp objects and factories and doesn't pop while SpongeBob ends up getting hurt.
In Bubble Buddy, Bubble Buddy drives an automobile home. In this episode, he rides an airplane home, stating he must have moved further away.
Despite Bubble Buddy's name in the title, he rarely appears in the episode.
This is Bubble Buddy's second appearance after 11 years.
Mr. Krabs was able to remember that Bubble Buddy still owes him money from "Bubble Buddy." This is the only use of legitimate continuity in the entire series.
After SpongeBob reads the letter from Bubble Buddy, the spots on Gary's shell swap colors.
When Shiny erases the moustache from Squidward's painting, no ink is seen on his torso; and the moustache could not be erased without touching the nose.
When SpongeBob and Shiny walk out of the pitchfork factory, SpongeBob has a pitchfork in his head. In the next scene, it is gone.
In Indonesian dubbing, the dubber made mistake by mispronounced Shiny as "Saini," not "Syaini."