A sunken oil tanker on the lip of an underwater volcano sends the city into a panic. Admiral Bubbles uses a device to switch bodies with Beanie. He puts Beanie in a jar of water and takes control of the submarine.
Beanie has long suspected that Mr. E, the mysterious owner of the local pet shop, is a space alien. Admiral Bubbles stumbles upon new evidence to support Beanie's theory.
Beanie offers to play on the basketball team after Elwood is injured. Admiral Bubbles launches a sinister plan which centers on a uniform that gives special abilities to the player.
Beanie's struggles in school leave him facing the possibility of summer school. He and Admiral Bubbles devise a cheating scheme that makes Beanie the best student.
With school out for the summer Beanie heads off to family camp and brings along Admiral Bubbles. The wilderness turns vicious as Admiral Bubbles creates a mutant form of poison ivy.
Admiral Bubbles is mistaken for a ghost when he interrupts a neighbor's psychic meeting. Admiral Bubbles decides to cause even more commotion by scaring the entire floor.
Beanie has a dream come true when his favorite TV show comes to town to make a movie based on his script. Chaos ensues on the film set as Admiral Bubbles tries to steal the lead role.
Beanie brings along Admiral Bubbles as he visits his grandparents' farm, but his vacation turns hazardous as Admiral Bubbles discovers a secret weapon.
When Beanie and Elwood do a school science report on earthquakes, Admiral Bubbles finds out that the town is built on a fault line- and he could invent a machine that would easily destroy it.
Admiral Bubbles decides to create a garbage monster- it turns out to be harmless, but very smelly. So Beanie teaches his goldfish a lesson by locking him up in a box with a skunk.
Admiral Bubbles plans to use the city's old incinerator to unleash a toxic cloud of pollution. So he disguises himself as a miniature blue whale and calls on Kevin Kelp to rescue him from his fishbowl in Beanie's bedroom.
Beanie enters Admiral Bubbles in a televised pet contest. But at the studio, a crazed sushi chef sees his opportunity to make the fabled "Bubbling Fish Teriyaki.
Admiral Bubbles tricks Mom into thinking she's accidentally killed him. So she flushes him and buys an identical fish as a replacement, hoping Beanie won't notice.
Admiral Bubbles has a plan to send fiery cockroaches to the North Pole where they will multiply and melt the polar ice cap- and Beanie has to stop him.