Lanny returns from the Evil Castle and uses an Evil Thorn to make Brady evil.

The kings discover that they are about to be forever remembered by their Chicago high school class as having thrown the worst party ever. Against Mason's advice they bring the entire class to Kinkow for the best Beach Party ever. Lanny switches beach signs and the party heads for the hunting grounds of the giant Kinkow Sand Maggot who has its own ideas for party snacks.

Boomer, Boz, Mikayla, Mason, and Lanny watch Candace's show revealing the mysteries of Kinkow, causing Boz to have doubts about being Co-King. When a temple is discovered belonging to an ancient evil named Kaita the Bat Rider (whose mummy is in the possession of the Tarantula People), Candace is trapped inside and the entrance is sealed by a force field that only the Kings can get through.

With Kaita the Bat-Rider at large with his army of undead zombies, Mason and Mikayla use the forcefield to come up with a counter-attack against Kaita's army. Boomer and Boz also have an encounter with the ghost of their parents who encourage them to use their bond to defeat Kaita the Bat-Rider.

When Mikayla's ex-boyfriend Lucas (a pirate who broke her heart) refuses to participate in the official Kinkowian Dumping Ritual, the kings track him down and discover that Lucas looks just like Boomer. To help out his quest to finally date Mikayla, Brady makes Boomer impersonate Lucas and pretend to go through the official ceremony, but the plan backfires.

Boomer and Brady discover Vault 14, a secret vault which protects Kinkow's most mysterious and powerful artifacts. They find the Duplicatus Plantus, a plant that copies anything it touches and make clone of themselves. The clones fill in for Brady and Boomer so that they can go surfing, However, clones want to replace Brady and Boomer forever.

Boomer and Brady find an ancient pocket watch.

Boz's monkey antics ruin a double date.

When the castle mysteriously explodes, Boomer and Brady are taken to court and forced to relive their most embarrassing and heroic moments through video clips when they try to prove to the jury that they are not guilty of the unlikely event.

A kid from Boz’s past arrives with a devastating secret that could ruin Boz’s reputation.

While Mason is out of town, the twins hang out with a bunch of mermaids and Mikayla turns into one herself.

Boomer goes to Chicago in an effort to convince Rebecca's father to let him see her after he forbids them to be together. Boz tags along and searches for a safe place to hide the Bat Medallion. Meanwhile, a menace from the past launches a surprise attack on the kings and it is revealed that Rebecca's father used to be part of the Tarantula tribe. As a result, he erases Rebecca's memory of her relationship with Boomer to keep her safe.

While trying to prove that they are the Kings of Legend, Boomer and Brady accidentally bring Zadoc, an ancient evil statue, to life, consequently putting the entire island in extreme danger. The twins cede the throne to Lanny for the better of Kinkow and depart on a balloon voyage back to Chicago for good, until the balloon catches a wind and sends them plummeting straight to the Dark Side of the island.

Boomer fears that Mikayla and Boz's budding friendship will blossom into a crush and he'll lose another brother to a Mikayla preoccupation. He gives Boz and Mikayla a Dirt Fairy potion so they'll dislike each other, but the potion is too potent and sends them into mortal combat instead.

When Boomer and Boz tarnish Mikayla’s chance of beating Mason for “Guard of the Year,” they feel guilty and secretly set out to help her by putting themselves in danger.

The island is infested with giant mukarats after the kings offend the troll people responsible for keeping the creatures under control.

The twins must save thier island from an errupting Volcano that they awakened. To do this they must cross into the dark side of the island and find a replacement rudy which is a task imposible to do. Lanny tells the villagers that Brady and Boomer are dead so he can become the next king.

Mikayla comes down with a fever and starts to turn into a Waka Waka Bug. So Boomer and Brady go to the Waka Waka Bug's hive to try to get the rare medicine to cure her.

A kid from Boz’s past arrives with a devastating secret that could ruin Boz’s reputation.

When one of the Kings' stunts gets Mikayla suspended, she calls them horrible bosses and quits her job to work at a fast food restaurant.

The kings are transformed into unrecognizable versions of themselves after they fall under a spell, and must dance with the fairest girls in the village to reverse their condition.

The kings are trying to act grown-up and impress the ladies only to find out their dates are luring them into becoming the source of power behind a fountain of youth.

Boomer and Brady join the Kinkow Fight School

Brady finally musters up the courage to ask Mikalya out, by using a note Lanny wrote for him, but he reconsiders and decides to ask her in person; when Brady attempts to retrieve the note, Mikayla mistakenly assumes the note is from Boomer, and he learns that before dating a girl in Kinkow you must be hunted down by her father. During the night while Boomer is getting hunted, Brady tells Mason that he is the one who wants to go out with Mikayla. Mason starts hunting Brady. Brady spits an egg at Mason, knocking him out. In the morning they go back to the Kingdom and Brady asks Mikayla out but she says no, because he humiliated Mason in front of the people of Kinkow.

Fed up with Brady's unusual habit of becoming a sleep ninja at night, Boomer impulsively moves out. But when his new landlord Charlotte turns out to be a former Tarantula Person and transforms Mason into a cold-blooded terminator, Boomer must turn to his brother for help.

The head chef quits when he is ordered by King Boomer and King Brady to prepare a steak cake when he was supposed to be making a very important meal for a giant ogre who is about to wake up from annual 10 year sleep, and when the ogre wakes up and demands food, the kings have to make a dish for him to save the island from his wraith.

Boz defies Boomer's warning and goes to the Dark Side. He finds a baby and brings it home, causing the Tarantula People to threaten war because it was their baby prince.

Mikayla finally has enough of Brady's constant flirting and tells him that their friendship is at an end and it would be only professional from that point on. Later she and Boomer seem to be getting closer as their share a hobby of Kinkowian poetry slams. Brady in a fit of jealousy, outlaws the poetry trying to end the new friendship. And the fight is on.

Brady tries to unite two conflicting tribes to impress Mikayla, but things didn't go as he planned to be.

When Boz sets out to help Boomer make his childhood dream of becoming a professional athlete come true, Boomer believes he's a natural at the dangerous island sport of Thumb War. With a chance to become a pro thumb warrior, Boomer wagers the castle and loses, only to find he's been conned by a Dark Side crook.

Boomer teaches Boz the fine points of being a brother, but breaks one of the bro-mandments.

Boz and Boomer become stuck together after Boz wishes they were closer.

Boomer opens the teen hotspot of his dreams and hires Brady as his assistant. When Boomer fires him, Brady spitefully opens his own club across the way inside a crypt upon being guided there by Lanny. When Brady performs a new song for the crowd with the lyrics having been provided by Lanny, the club is overrun by zombies that have been awakened by the song. Now it's up to Boomer to put his differences aside and rescue his brother.

Boz decides to address Boomer's lack of survival skills and forces him to go camping.

Brady and Boomer must endure a King Challenge that tests their smarts, strength, and spirits. When Mikayla realizes the boys won’t pass the challenge, she agrees to help them, but the plan goes horribly wrong when Mikayla and Lanny are transformed into Boomer and Brady.

When Boomer discovers that he and Boz do not have any brotherly memories like he and Brady do, he sets out to recreate a ski-trip from his childhood. But, when Boomer finds that the land he wants to build his resort on is occupied by Yetis, he removes them from the land and attempts to teach them how to be civilized.

When King Brady misses his favorite sneakers it's King Boomer that blames a monster that nobody has seen except him that he calls Mr Boogey. Nobody believes him, thinking he got rid of the stinky shoes. However Mason has been keeping a secret about the creature for years. After Mason is captured by the creature it's up to Boomer to prove Mr Boogey is real.

Boz tries to impress his ex-girlfriend with a charade of wealth. She doesn't actually care about Boz and is only there to take his made up riches.

Zadoc's minions capture Lanny and try to squish him with a huge rock. Lanny hands the throne back to Boomer and Brady. Mason goes after Zadoc and sees Boomer and Brady fight and defeat Zadoc and realizes that maybe they are the kings of legend.

When Boomer and Boz find out Lanny is mad at them, they buy him his own island. But when they learn that the source of their wealth lives on that island, a gopher that produces gold, they try to get the gopher back without Lanny finding out.

It's the kings' birthday and for their royal present, they each get one wish that will come true. Right before blowing out the candles, Boomer learns that Brady has been bragging to the entire island that he is the older twin. Boomer uses his wish to find out the truth about who was born first, while Brady's wish is that Mikayla compliments him all day. Boomer travels to the center of Mt. Spew to meet with the volcano's Oracle and learn who is the older king, but the younger brother will no longer be co-king if it is known who the older brother is. So Brady, Mikayla, and Mason chase after Boomer.

The Bat Medallion that Boz in Rebecca's apartment has dragged Rebecca to Kinkow. When Mikayla confiscates the Bat Medallion, Kutamungo captures her and the Bat Medallion in order to revive the Tarantula People's leader Kaita the Bat-Rider. The Kings fear of Kaita the Bat-Rider turns into revenge when they discover the evil Kaita is responsible for their father's death.