The Mario Bros., Princess Toadstool, and Toad protect the Mushroom Kingdom against the evil forces of Bowser and his seven Koopa Kids.
Koopa turns Kooky, Bully, Big Mouth, and Cheatsy into gigantic ninjas to apprehend Prince Hugo of Giant Land.
Koopa warps the White House, along with the President and the First Lady, to his castle and makes Kootie Pie Empress of America.
Hip and Hop kidnap the sarcophagus of a prince whom Mario resembles. Their actions awaken the prince's mother, who believes Mario is her son.
While stealing oil from the sultan of Desert Hill, Cheatsy turns Kootie Pie into a human so she can fool Mario.
When Princess Toadstool challenges Koopa to an election over leadership of the Mushroom Kingdom, Kooky uses a nice guy potion on Koopa to make all the voters like him.
In order to show Cheatsy how to be just as rotten as he is, Koopa lures Mario and friends to his castle and threatens to blow them up using a big army of Bomb-Ombs.
When Princess Toadstool and Toad take a vacation in Hawaii, Kooky uses a robot princess to try and take over the Mushroom Kingdom.
Kooky and Koopa try to go back in time to stop the Super Mario Bros. from ever going down the drain in Brooklyn, but their plan backfires, turning them all into babies.
Fed up with Koopa's ways, Kootie Pie and Big Mouth bring a Hollywood movie monster to life and convince him he's their real dad.
Mario and Luigi enter a wrestling match so they can give the prize money to Toad to make up for a donation to the Mushroom Orphanage he believes he lost.
When Mario and Luigi get fed up with each other, Luigi soon finds himself having to save his brother from Koopa and Kooky.
Koopa brings TV hero Mighty Plumber to life and tricks him into robbing the Pipe Land Treasury.
Toad loses a magic wand to the Koopas.
Mario and Luigi wind up babysitting a brat from Brooklyn who finds his way into the Mushroom Kingdom.
Mario, Luigi, Toad, and Princess Toadstool seek the Doom Dancer Music Box in Koopa's Castle, but when the Koopas find out, they go after it themselves.
Koopa kidnaps Milli Vanilli and forces them to perform exclusively for Kootie Pie.
When a Real World family drives into the Mushroom Kingdom, the Mushroom People and the Koopas mistake them for aliens.
While wearing a Frog Suit, Mario almost drowns, but he is saved by Holly Mackerel, a mermaid princess. Holly falls in love with Mario and tries to marry him.
Koopa recruits a criminal from the Real World to teach the Koopalings how to commit crimes.
Hip and Hop turn Luigi and the King of Ice Land into dogs and run off to cause mayhem in Florida.
Kooky uses his new "Raiser Upper" machine to levitate everything in the Mushroom Kingdom to the sky.
After trapping the Super Mario Bros. and Toad in the Mushroom World, Koopa orders his kids each to take over one of Earth's seven continents.
Kooky and Cheatsy use a special paint to turn all the Mushroom People either red or blue and trick the two colors into hating each other.
When the Koopalings are forced to dispose of their garbage, they have it dropped on the Mushroom Kingdom and later Brooklyn.
Koopa gets another present for Kootie Pie - this time he plans to use his Doom Sub to chase everyone out of Venice, Italy then warp the entire city to Dark Land so Kootie Pie can have her own water park. The Mario Bros. are approached in Desert Land by an Italian gondolier and since Mario has a passion for the country of Italy, they couldn't resist. Armed with Frog Suits, can they stop Koopa in time?
Kooky has developed a pendant for King Koopa that will grant him the powers of the Mario brothers, but it can only be used in the real world. Koopa uses that to his advantage and lures his unsuspecting enemies into the real world using Luigi as bait. But the Princess manages to contact Toad, who races to get as many power ups to the Mario brothers in time.
