Season 3

Seven eavesdrops on the others, learning their secrets so he can pretend to read their minds. Impressed, they arrange a big show for all the neighborhood kids, but of course Seven's act falls flat. He then admits he eavesdropped and apologizes to everyone.

After learning all about the moon from "Buzz" Three, Four decides to build a spaceship and go there himself. The others join in the spaceship they made, but their finished contraption won't go and lift off the ground. Four overcomes his disappointment, realizing that they still had fun, and learned a lot along the way.

The monsters wait impatiently for their cupcakes to finish baking. Since time passes more quickly when you are doing something, they partake of some typically bizarre monster activities, such as building an exact replica of the Taj Mahal in their backyard and swimming the English Channel in under 10 minutes.

Spurred on by hopes of winning a trophy and creamed corn, Six competes in a bowling tournament.

Two is trying to write a song for a contest and needs peace and quiet! His brothers and sisters are eager to help but being quiet is a real challenge for six rambunctious monsters!

Six wakes up from a bad dream and is too scared to go back to sleep. Each monster shares their worst nightmare and soon they are all shaking with fear. Mom reassures them that bad dreams are normal and can't hurt them, and the exhausted monsters fall right to sleep.

Tired of sharing a room with her siblings, One gets her wish when the monsters' estranged uncle comes over and offers to swap his mansion for the monsters' home. At first, it seems that having a new home is great, but when the monsters didn't like having their own rooms, they decide to find their mom and want to tell her that they want to switch homes again. During their journey to find Mom, they fell down the laundry chute, entered a hall of mirrors, a large bathroom, got sucked into the air tunnels, entered a room where the stairway are upside down, a room with a trampoline and finally both encountered and chased by large orange cat but near escaping it, they decide to head back to their house and asked their uncle to switch back, but it was revealed that he was actually their mother in disguise and the mansion they lived in was only rented for one day.

Four shows Five the difference between boys and girls when he finds him playing with doll figurines of a space man and a farmer's wife in the sand box; however, he is proven wrong three times (once, there are boys in Six's ballet class [not to mention the teacher is a man]; then, One is skateboarding; and finally, Two and Seven are knitting [not to mention Mom has a bowling ball]). Meanwhile, Three, who is a troubadour in this episode, tries to consolidate Four and Five to share their dolls. He sounds like singer Bob Dylan. His voice also sounds a little bit like Johnny Cash. He plays his mandolin when he talks. Nevertheless he sings too.

A mysterious letter arrives for Pirate Captain Three, instructing him and his monster crew to solve a series of puzzles to find a buried treasure in their own back yard.

When it is time for the monsters to give some of their old toys away for charity, Six does not want to give away her rocking horse Sparkles. When her siblings tell her she has to, she decides to run away not wanting to part with the toy. This results in a search around Centerville for Six and her toy rocking horse Sparkles. The other six monsters start to wonder if it was right for them to tell Six she had to give up Sparkles when she wasn't ready, but when events lead up to Six seeing Mary's little cousin, Carrey play with Sparkles, Six begins to cry when Sparkles was in the water, so she decides for herself that she is ready to give the toy up by letting Carrey keep it.

Six promises Mom she'll take out the trash this week, but instead she pawns off the chore on the other monsters. They simply stash the garbage bags throughout the house - out of sight, out of mind! When the whole thing blows up, Six must face the consequences of her broken promise to Mom, so then Six starts to cry.

During a baseball game the ball takes a bad hop and hurts One's wing. After a few days rest, One's wing is better, but she's afraid to rejoin the team. A talk with "Trot Along" Three convinces One that she's just got to "get back on that horse" and face her fears.

When Five is having trouble learning how to somersault, his siblings try to give him advice the same way Mom usually does - by telling a story. They tell some crazy fairy tales but only when Mom returns home is the moral of the stories revealed - "try, try again". This inspires Five to try, try again until he accomplishes a perfect somersault.

The whole family is on a shopping trip to a big department store. Six isn't paying attention as Mom gives instructions, and when she gets lost she doesn't know what to do. Finally a security guard reunites the family and Six learns she should always listen carefully to Mom's instructions. Noticing what happened to Four, Six begins to cry about Four.

Mom is sick in bed and One promises to supervise the others in doing her housecleaning chores. When things start to go wrong, One doesn't ask Mom for help, preferring to tackle the problems herself. As a result, the monsters' cleaning efforts soon spin totally out of control and Mom must step in to restore order.

Similar to the story of Boy Who Cried Wolf, Two pretends to be injured after his stomachache is cured. But he soon realizes that lying about himself is not fun. Mom tells the story of The Girl Who Cried Sloth.

It's bedtime but the monsters aren't sleepy. Four asks the magic Plooky to make everything backwards so they don't ever again have to go to bed. He wishes it can be daytime forever. When night turns into day, they run outside to play… right into a crazy backwards world! Soon everyone is wishing for things to be back the way they were.

Four accidentally leaves the water on in the sink and learns an important lesson on about how you should not waste water.

While planning a backyard camp out, One gets carried away with tattling on her siblings to Mom. She's telling on them for every little thing they do, so the other monsters leave her to camp out all alone. This isn't any fun, and One realizes that you can take 'telling' too far.

Three (as Captain Threemo, a parody of Captain Nemo in 20,000 Leagues under the Sea) uses his imagination with the other six monsters in a submarine while he is waiting for a submarine he ordered. Three speaks with a Cockney accent in this episode. He sounds a little bit like Roger Radcliffe and Skylar without his accent from Elena of Avalor.

Two feels like his nose is an object of ridicule because, after Mary explains a story of Pinocchio, the other monsters mock him for how long his nose is.

At a baseball game a very loud Four annoys Six so much she wishes he couldn't talk at all. Her wish comes true when Four loses his voice and the monsters go on a search for it all over town. Back at home, Mom prescribes bed rest for Four, and soon his voice is back as loud as ever.

One decides to keep a crab as a pet and names him Buster. But soon, she realizes that Buster will be even more happier in his natural habitat.

The monsters notice the Zoo Panda is sad and lonely in a neglected habitat. The Zoo manager explains they haven't the resources to improve it. So the Monsters try to find ways to raise money, but everyone finds it silly when Seven collects Pennies.

Passing by a construction site, Two overhears a bad word. Repeating it back at home, he enjoys the shocked reactions of his siblings. Mom tells him a story about how bad words upset others and Two resolves to never say the bad word again.

Seven wants to play a new board game but doesn't want to read the game's rules.

Three is jealous of his siblings, so he pretends to be a baby. Soon Three learns that everyone loves him for who he is.

Four and Five have several arguments which escalates into the two formerly inseperable monsters deciding they do not want to speak to each other anymore. Fortunately the ever wise Mama finds a solution by making Four and Five clean the shed. It isn't long before the two are up to their old selves and are laughing at each other's antics.