All three series focus on the characters of Mario and Luigi assisting Princess Toadstool and Toad in thwarting the plots and schemes of King Koopa.
The episodes would re-air in 1990 under the name Club Mario, which replaced the show's original live-action segments with newer five-minute sequences.
A young girl (Danica McKellar) arrives at Mario and Luigi's claiming to be an orphan without a family or a place to go, so the plumbers invite her in for a stay.
Dr. Frankenstein (Eugene Liebowitz) asks Mario and Luigi to help him with his experiment in promising his monster (Craig Armstrong) a normal brain.
A bop on Mario's head giving him amnesia forces Luigi to call in Dr. Sigmund Fruitcake (Larry Gelman) for help.
Mario and Luigi's bossy mother (Captain Lou Albano) and aunt Luigeena (Danny Wells) come to visit.
Luigi is asked to fix Magic Johnson's high school basketball trophy but Mario unknowingly throws it into the furnace.
The Grand Pooba of Plumbing (Marty Allen) arrives to announce Mario and Luigi have been elected Plumbers of the Year.
Mario and Luigi's hillbilly cousins make themselves too much at home and end up socializing with a girl named Ellie Mae (Donna Douglas).
[5] Mario and Luigi meet Fred Van Winkle (Norman Fell), a man who has just woken up after sleeping for 60 years.
When the rest of her band is unavailable due to their flight being late, Susanna Ross (Regina Williams) stops by and asks the Mario Bros. to act as backup singers.
Mario and Luigi, anxious to find out what prize they won in a sweepstakes, consult a fortune teller (Kaye Ballard) for help.
Mario and Luigi want to turn their apartment into a bed and breakfast, and pretend that George Washington (Ed Metzger) was once a guest.
When Tulio "the Wrench" becomes angry with Mario for asking his sister out, the brothers turn to help from Obi-Wan Cannoli (Arsenio Trinidad).
Mario starts having strange visions of his grandmother, and he asks The Old Psychic Lady with the Evil Eye Who Reads Fortunes and Knows Everything Before it Happens (Elaine Kagan) for answers.
Soviet general secretary Mikhail Gorbachev (Martin Gardner) comes to Mario Brothers Plumbing after hearing they make the best pizza.
The Queen of England, Elizabeth II (Vicki Bakken), is sick of being treated like royalty, so she visits Mario Brothers Plumbing.
The Marios become fed-up with the singing of would-be opera singer Mrs. Gammliss (voiced by Karen Hartman), who lives in their apartment building.
Princess Toadstool is fed up with Koopa's antics and challenges him to try and win the Kingdom from her fair and square in a democratic election.
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.
Luigi and Princess Toadstool make toys and wrap gifts, Mario dresses up as Santa Claus, and Yoshi pulls the "Cave-Sleigh".
With the Cave People under his control, Koopa puts the Marios on TV as the fall guys in Dinosaur Wrestling.