Yang hurts Yin's feelings when he starts training under Ultimoose.
Master Yo gives his young protégés a test, which involves having them watch a seemingly harmless rock named Hershel.
Carl, the Evil Cockroach wizard, gives Yin and Yang a new TV with only one remote. Yin and Yang fight over the remote, giving Carl a chance to destroy them.
Yin and Yang tell Yo that he is old, and Yo makes them pick up his medication. Yo throws a party to look cool, but Yin and Yang make Yo's old enemy, Kraggler, mad. Kraggler turns everyone, except Yin and Yang, into old people.
Yin and Yang's bad traits combine and take the form of a green rabbit.
Yang fakes being a Woo Foo Warrior to impress a girl. To prove his skills, he has to take out a huge steel beetle.
Yin and Yang try to teach Yo that it's not good to boss kids around, but little do they know, Herman the Evil Ant is waiting for the panda to leave so he can conquer the world.
Yin and Yang get into a fight while cleaning their room, and when Yin costs Yang the world record at a video game, he refuses to shower until one of them cracks and apologizes. But Yang is soon encouraged to clean himself up when his odor attracts the amorous advances of Malodia the Elephant, Princess of the Stink Aardvarks.
Yin comes down with a case of the Woo Foo Flu, an illness that causes her to bend reality whenever she sneezes. Master Yo orders Yang to take care of her while Master Yo concocts an antidote for the Woo Foo Flu. However, Yin later gets captured by Carl - who intends to exploit her illness so it can help him take over the world - and Yang may have to get himself sick to save Yin.
Yin and Yang use Zarnot to boost their popularity by lying. When Zarnot becomes huge, they must prove that they are telling the truth.
Yang uses the Glasses of Unlimited Smartness to pass the test to get to the next level of Woo Foo training. But Carl tries to get Yang to help him grow huge.
Yin's Woo Foo Aura gets out of control, trying to save the environment and escapes Yin's body, destroying the town.
Yin falls in love with a person named Brett who actually turns out to be Yuck.
Yin and Yang have to stop Pondscum from stealing Yo's golden chair.
Kraggler uses the cronalogicum to trade ages with Yin and Yang so he can become young again.
Yang won a doll at the county fair for Yin, but the doll is actually Zarnot.
Yo tells Yin to go to the valley of the two-ni-corns and find a rainbow mane The Gnu to fix her toy. Meanwhile, Yang is taken over by Ultimoose.
Saranoia makes a snow day so that Yin and Yang can play outside and Yin may have a day off, as she holds an obsession with Yin's future
The Night Master rebuilds his armies that were frozen years ago by Master Yo. Little do they know, Yin and Yang are involved in his plan.
Yang is thrilled that the CPK (Chung Pow Kitties; a pastiche of Hello Kitty and Powerpuff Girls), a rock band made of cats with mad ninja skills in town. Not only that, but they also appear on Broadway and are looking for a new member. Having a sharp sword is a requirement. Yang's bamboo sword isn't sharp enough, but Master Yo refuses to give Yang a new sword. Yang plots to steal weapons from the Forbidden Armory to try to make the cut.
Yin meets a hamster who loves to clean while she is out buying cleaning supplies. The hamster reveals himself to be Fastidious, and asks the Woo Foo students to help him defeat some of the spirits who have been making a mess. However, there is something sinister about Fastidious.
Yin and Yang are fishing when a group of female pirates appear. They act really nice towards Yin, but not so much towards Yang. Are these pirates all they appear to be, or is there something else about them?
Carl wants to use his mother's destructive jewelry for his nefarious purposes (especially since she never wears them) but his mother, Edna, won't let him. Meanwhile, Yang pulls a practical joke on Master Yo by posting his bio on a website for dating service for old people. Master Yo's blind date turns out to be Edna. Can Yin and Yang break up this relationship that's not meant to be before Carl can take advantage of his mother's absence?
A special combined episode consisting of the last three episodes of Season 1. Episode 24: Shadows and Light / The Truth Hurts Episode 25: Who Knows What Evil Lurks Episode 26: Night Fall
Master Yo shows Yin and Yang that black-and-white films can be scary.
Yin uses the misfortune cookies on Yang to take away his good luck.
Yang is really interested in a girl named Lina, who is Yin's really good friend. The trouble is, Yang's behavior turns Lina off. So Master Yo suggests that Yang should try to be more like Yin in order to make Lina like him.
Yang acts like Yin to impress Lena.
Yin and Yang host an awards show for evil Brother Herman.
The Night Master hides in Yang's imagination.
A new master is in charge.
A fun road trip serves as a cover for a covert operation.
Dressed as a donkey, Yin and Yang infiltrate a bad-guy convention.
Saranoia returns.
Yin and Yang meet the legendary Woo Foo twins.
Coop teams up with Yin and Yang to win back an ancient Woo Foo artifact.
Herman and Carl want to give their mom a pair of rabbit's feet for luck.
Master Yo's ex-girlfriends show up.
Yang finally makes some guy friends, but they're not who they say they are.
Brother Herman attacks while Master Yo is away.
A heavy-handed hero teaches everyone a lesson.
Yin and Yang wonder if Master Yo is really evil.
Yang acts up in a video game.
Yin and Yang are put on trial.
Yin and Yang follow Yuck to a terrifying place... inside Master Yo.
Shaggler turns into a baby.
Yang uses an ancient tool to end Yin's constant pursuit of popularity.
Yin and Yang are promoted.
Information on Yin and Yang is leaked to the Night Master and the twins try to find the culprit.
The Night Master plots to kidnap Master Yo so he can plunge the world into darkness and be free.
Yin and Yang prepare to go on vacation. Coop returns and tried to warn them of The Night Master's energy escaping, but they ignore him until it's too late.
Coop's mom is throwing a "welcome back/thanks for saving the world all by yourself" party, and Yin and Yang are the only ones not invited. Meanwhile, three flunkies join together and try to get into The Night Master's fortress. However, they need the spare key, which the Night Master gave to Coop!
Yin and Yang are pitted against each other in a fight.
Yin takes credit for saving the mayor, without acknowledging Yang's help.
Yang's brain becomes controlled by a villain known as Mastermind.
Master Yo faces an old nemesis he has never been able to defeat.
Yin and Yang uses a magical bracelet to make fooplicates of themselves until Yuck returns.
Melodia the Aardvark Princess returns to claim Yang until Fastidous makes Yin mad with the Stink Aardvarks.
Carl casts an ugly spell on Yin and Yang after Yin insults Carl and calls him a "buglie".
Yin and Yang learn self-control at an institute, but its founder, Ultimoose, may have more sinister plans in store.
Yin and Yang get a lesson in cultural enrichment when a foreign exchange student from Redneckistan named Jobeaux shows up. Meanwhile, the Chung Pow Kitties return in search of a powerful Woo Foo artifact. Yin and Yang suspect that there is more to Jobeaux than meets the eye.
Master Yo is sick of Yin and Yang disrespecting him. Yin and Yang are sick of Master Yo treating them like babies. When young Kraggler switches ages with Yo (part of a diabolical plan), Yin and Yang are forced to babysit the three-year-old Yo, and he reveals how powerful (and bratty) he was as a child.
Yin and Yang attempt to defeat a half-human, half-bull monster.
Carl forms a league of evil with three other villains when they all rent an apartment together.
Yang endorses a toy line for money but doesn't realize that the toys are harmful to children.
Yin, Yang and some of their friends accept a free vacation to a mysterious island, not knowing that it's a trap set by Smoke.
Ultimoose and Yang search for an amulet that will give them all of the Night Master's powers.
Yin reluctantly goes on a date with Coop, and she falls under his evil spell.
Carl tricks Yin into eating seeds that make her doubt everything.
Mr. Pondscum realizes he isn't a goldfish but a polliwog.
Carl magically switches brains with Master Yo in an attempt to destroy the Woo Fo warriors.
Yin takes in some seemingly harmless green creatures as pets, but Yang believes they are dangerous.
Yin and Yang become addicted to a TV show about a superhero but learn they should focus instead on becoming heroes in real life.
ang loses his emotions after he is zapped by Fred.
When Yang separates himself from Yin and Master Yo, he saves a robot, and they start to act like brothers. But Yin is feeling suspicious and jealous and discovers the robot is actually a spy made by Zarnot sent to destroy Yang.
When Yang constantly insults and embarrasses Roger Skelewog and his father in front of everyone, he and Roger go on a Reality Show. On the show, an all-out brawl erupts between Roger Skelewog Sr. and Yang.
Yang develops a rare tooth condition and could end up as dinner on Edna's table.
Carl traps Yin and Yang in a sitcom with a magic remote.
Yang receives a powerful artifact, but it's a skirt and he refuses to wear it.
Carl attempts to blot out the rays of the sun.
When Yang finds out that Master Yo knows a form of fighting known as Clown Fu, he wants to learn the various techniques for himself.
The Chung Pow Kitties are desperately trying to claim the Licking Stick in the Woo Foo Weapon armory as their very own.
Yin and Yang begin magic training at Camp Magic Pants and become involved in pranks that get them into trouble.
Yang takes a job at an amusement park that turns out to be anything but fun.
Yin and Yang attempt to prevent Carl from using a pair of magical slippers for evil purposes.
Yang casts a spell that makes him disappear and unable to be heard.
Yin and Yang are magically stuck together by Mastermind so they will learn to cooperate with each other.
Yin hosts her first slumber party but she drives everyone crazy with her strict schedule.
Badfoot tries to steal a powerful artifact from Master Yo.
Yin and Yang play a cursed video game, which requires them to keep dancing or die.
Yin and Yang's former enemy Yuck returns and claims to be a reformed rabbit.
Yin and Yang meet a seemingly sweet old lady who really wants to fatten them up and serve them for dinner.
Yin and Yang attempt to stop Eradicus from launching the destructive Dark Tomorrow.
Yin and Yang want to become bears, but an evil ranger tries to get them mauled by the animals.
Yang gets a pet but it runs away after he neglects it.
Yin tricks a clam into liking her so she can steal his jewels.
Zarnot creates a robot girlfriend for himself.
Yang seeks out a vigilante named Possum Panda, but he discovers solo crime fighting isn't all it's made out to be.
Yang resorts to talking to a dummy after Master Yo leaves town, which infuriates Zarnot.
Eradicus creates a monster that gains power by consuming everyone's fears, and Yin and Yang try to destroy it.
Yin and Yang compete with the Manotaur in a game of chance.
Carl disguises himself as a normal kid to stop Eradicus from carrying out an evil plan that would make everyone bad.
Yin and Yang are tricked into entering a dangerous car race.
Yuck causes Yin and Yang to swap personalities so he can weaken them and seize power.
Zarnot disrupts Master Yo's holiday plans.
Yin and Yang team up with different partners to fight a common enemy.
Yin and Yang tease a pizza-delivery man, so Master Yo makes them deliver pizzas on time or else become a slice themselves.
Master Yo goes to extreme lengths to get Yin and Yang to take fighting seriously.
Mastermind attempts to destroy the city while Master Yo is absent, so Yin and Yang assemble an army to fight him.
Carl tries to make Yang his evil minion.
Yin and Yang are tricked into starring in a movie that is actually a trap set by Eradicus to destroy them.
Master Yo's recliner is discovered to be inhabited
Master Yo tries to teach Yin and Yang how to prevent Ella Mental from reading their minds.
Yin searches for a rare wild beast to protect it from hunters.
Yin and Yang's dirty-laundry pile turns into a monster and escapes into town.
President Muffins enlists help from Yin and Yang in a bid to get reelected.
Yin and Yang throw a party, but Eradicus plans to crash it so he can destroy them.
Yin falls in love with Coop once again, but their relationship blinds them to Eradicus' plan to destroy the town.
Leena meets Jason Earles and Mitchel Musso when she lands in Earles' backyard in Hollywood, where the two friends argue over who has the best hair.
Eradicus tries to divide the Woo Foo army in order to conquer it. He then takes a vacation at a spa where Master Yo is staying, and the two enemies attempt to get along for the duration of their stays.
Yin and Yang search for their parents after Yin is drained of her aura and only a transfusion from a parent will save her.
