Mumbies Madness is the 84th episode of Kirby: Right Back at Ya!. It comes after Teacher's Threat and before A Sunsational Surprise. In this episode, an angry Mumbies that Professor Curio discovers terrorizes Cappy Town after it is dug up.
At the start of the episode, Kirby is seen sleeping in Tokkori's nest instead of his own bed. Suddenly, Tokkori flies into his nest and tells Kirby to wake up. Kirby eventually awakens and follows a mysterious clanking noise found by Tokkori, coming across a dig where Professor Curio has found a stone jar and is hitting it with his pick. Kirby greets him, whereupon Curio demands that Kirby leaves. Kirby leaves in fright as Curio now has green glowing eyes. The professor then turns back to his find, laughing insanely, while it unleashes green light.
Later, Kirby is found sleeping beside a rock due to his insomnia, but Tuff snaps him out of it because he and the Cappy kids need a new goalie for their soccer game. Professor Curio, now with an angry look on his face, pulls a cart with the artifact. Kirby is kicked in the air in his attempt to stop the enemy team's goal, landing on Professor Curio even though Tuff warned the archaeologist. Tuff then offers to help Curio push the cart, only for his offer to be turned down as the professor tells him he is fine. Tuff ignores what Curio says and prepares to carry out his offer, only to get startled as Curio pops in and tells Tuff to leave. Curio pulls the cart away, his strange behavior confusing Tuff again.
Later, at Castle Dedede, Tiff asks Tuff for information on why Professor Curio was acting so mean. Tuff explains that Curio was hiding something he dug up. Sir Ebrum asks his children if Tuff is saying that Professor Curio is up to something. Tiff agrees with her father. Tuff states that Curio probably found treasure, but his mother interrupts him. Tuff continues with his explanation, only to get scolded again as Tiff tells him that Curio cares about knowledge.
Back at his house, Professor Curio lays out artifacts and books. Then, an irate Mumbies pops out of the jar the Professor found. Curio raises his arms, but the Mumbies screams and escapes Curio's home. As he does so, he heads towards Cappy Town. The creature first causes trouble in Kawasaki's restaurant. While preparing to leave, the chef notices that his window is broken. However, the Mumbies pops up in front of Kawasaki and scares him, stopping the chef dead in the middle of his speech. After he has finished scaring Kawasaki, the Mumbies leaves the scene of the crime.
The chief mechanic, Gus, has finished watching TV, so he prepares to go to bed. The mechanic is flabbergasted to see a glowing light outside his window. This is actually the light that the Mumbies Curio released earlier is emitting from his eyes, and is followed by the Mumbies screaming. A terrified Gus faints flat on his back as the monster screams at him, after which the Mumbies leaves off to scare the others.
Later, Kirby is asleep in his house, next to Tokkori. The Mumbies breaks into the house, scaring Tokkori. The Mumbies ignores the startled Tokkori as he looks at Kirby. The monster then turns his eye blue, screams, and latches onto Kirby. The terrified puffball runs around his bedroom and eventually manages to knock the monster off. Unfazed, the Mumbies chases Kirby out of the house and they run out the front door as Tokkori advised Kirby to run out.
The chase continues into the forest, where Kirby apparently makes his getaway. The Mumbies, undeterred, searches for him, catching Kirby off guard with a dark energy blast from his eyes. An unconscious Kirby is then dragged upward by the Mumbies, only to be saved by the break of day. Upon his release from the Mumbies, Kirby floats down in front of the Kabu priest. The priest warns him to be careful because the Mumbies will not relent attacking his prey. Disgruntled about his failure, the Mumbies returns to his jar. Curio just stares at his find in fear.
Back at the castle, Tiff is surprised when she hears about how Kirby was almost swallowed by a monster that broke their way into his house. Tuff asks if Kirby was hurt, but Tokkori claims that Kirby was fine before he went back to bed. Kirby returns, but his body is bruised. Tiff and Tuff roll Kirby over and find him asleep. Tokkori then suggests first aid, only to be glared at. The bird laughs about his joke and turns his back on the situation.
Meanwhile, Kawasaki reports having seen a monster in his restaurant and Gus that the monster's eyes looked like a car's headlights would. Mabel claims that it crashed through her room and she ran around screaming. Samo is angry by this and declares that the culprit is a scoundrel. Bookem, the Chief of the Police, asks the Cappies for their data on the monster. Kawasaki explains that it had long, scary teeth, and Gust explains that it was wrapped up like a mummy. The kids are terrified by this description. Tuff asks Curio for details on the monster. A startled Curio stutters in his speech, and Bookem asks him for more data. Curio waves his arms and runs off. King Dedede and Escargoon, meanwhile, are spying on Curio, commenting on how Curio is good at his job and how their plan to get rid of Kirby is a success.
Later that evening, the kids sneak into Curio's house, finding out that Curio is mixing a strange brew in his basement.
Kirby, meanwhile, is unconscious at his house. Tokkori and Tiff feel bad to see Kirby this way, realizing that the monster chased him all night. Tuff then breaks his way into the house, explaining that Curio is up to something weird. Tiff does not believe her brother until she sees that Mumbies are creatures of good luck and their discoverer will be blessed. Tokkori then realizes that the creature they saw was a Mumbies. The group then sneaks off to Curio's house, busting him again. As his "guests" accuse him of treason, Curio panics. Tuff then tries to snatch Curio's ladel, but knocks the jar off, and the Mumbies rolls out. Now angry, he glares at the trio and runs off. The trio watches as the Mumbies goes on another rampage. Tiff asks Curio how the creature arrived. Curio admits digging up the jar and breaking the seal. Tuff then wonders why the Mumbies is after Kirby, but Meta Knight appears out of nowhere and says that the book's content is all a lie. He then explains that King Dedede himself wrote the book, and the kids are baffled by what their new "guest" is saying.
Continuing with his explanation, Meta Knights explain that Mumbies are bioweapons that were seeded on different worlds to kill Star Warriors. Whenever it is discovered, their jar's seal is broken, allowing the Mumbies to cause trouble. Curio then reveals that he reexamined the book today and found that it was a fake. Tiff then asks for info on what his new potion is. The archaeologist reveals that it was an ancient brew used to seal a Mumbies up again. The kids, Curio, and Meta Knight conclude that Kirby needs help and rush off to his aid.
Kirby and Tokkori, asleep, are startled when the Mumbies breaks through their window attacks them with his bite. Kirby tries to knock the Mumbies off. Tokkori opens the door and Kirby rushes out and smashes his face on a tree, knocking the monster off. The unfazed Mumbies chases Kirby into a watermelon patch, where he loses Kirby. Kirby reveals his hiding place to the viewer, and eats the melon. At that point, an irate Mumbies catches and blasts Kirby with a laser from his eye. Kirby recovers from his fall and rushes to the castle with the Cappies and Mumbies after him. Tuff tries to get Kirby's attention as Tiff states that they must stop the monster. Meta Knight and Curio quickly follow. Kirby dodges left and right, avoiding the laser that the Mumbies is launching as the Cappies watch the fight. Kawasaki then yawns, irked that last night is repeating itself, while Gus believes he will not sleep tonight. Bookem asks why it has to be so noisy as the Mayor hopes for Kirby's return. Bookem states his hope that Kirby does not get eaten, but the mayor is doubtful. Gus then deduces their location to be part of the Kirby versus Mumbies chase itinerary, and the Cappies dodge as Kirby runs through them. Kirby tries to make his getaway, but the Mumbies manages to catch up to his target and corners him.
However, Tiff and the others have found Kirby, encouraging him to kill the Mumbies. The Mumbies turns his eyes blue and glares at Kirby. Kirby shoots back a glare of his own, but the Mumbies knocks him unconscious with his stare, which Meta Knight point out as a defense Mumbies can use against their attacker. Kirby then attempts to swallow up the Mumbies, but no Copy Ability is gained.
At that point, King Dedede appears in his limousine and Tuff scolds him for trickery. Escargoon (who rode in the limousine) appears and demands that Tiff prepares her goodbye because Kirby is dead. Dedede then pulls out a bomb, but his underling tries to stop him, knowing what will happen, but it is too late. Dedede throws his bomb. Kirby then devours the bomb, resulting in his transformation into Bomb Kirby.
Tiff, realizing that Kirby has turned the tables, asks the Kabu priest to send in a Warp Star, which Kirby boards. Kirby tries to bomb the Mumbies with his explosive arsenal, but the monster avoids it and counterattacks with his eye laser. Kirby reacts by blinding him with two bombs. Kirby then prepares a giant bomb and releases his weapon down at the creature, who dodges and latches onto Kirby. Kirby then kills his opponent by turning toward the sun as it rises as they are brought up by the Warp Star. Burning up, the Mumbies tries to escape, only to die as his body disintegrates. From their place in the limousine, King Dedede and Escargoon see that the sky is filled with sparkling lights. This notifies them that Kirby won. Kirby falls from his Warp Star and his friends rush out to congratulate him. Meta Knight informs Curio that no more Mumbies exist out there, and this one is out of commission. Curio apologizes for his "sloppy research and promises to be more careful," since it led to this predicament. Curio comes to Kirby's aid, asking the kids for info on Kirby's condition. Tuff states that Kirby needs his rest and Tiff tells him to have sweet dreams.
Before the end credits, King Dedede watches the moon but it turns into a bomb and explodes.
- Despite his position as a Star Warrior, Meta Knight does not become one of the Mumbies' targets. However, the Mumbies may not have noticed Meta Knight at all, keeping his eyes on Kirby.
- King Dedede apparently forgot about the Bomb Copy Ability.
- Mumbies does not have an ability to copy, but he can launch lasers from his eyes.
- Even though he is illiterate in A Novel Approach, King Dedede is, par Meta Knight, shown to have written down the monster's instruction manual perfectly.