"Reign of Gunters" is the twenty-fourth episode in the fourth season of Adventure Time. It is the one hundred and second episode overall.
Gunter attempts to take over all of Ooo with the demonic wishing eye and the pink kitten, while it sends a distracted Ice King away.
Ice King is in his room looking for his Demonic Wishing Eye. Gunter comes in and Ice King follows it to a hair brush. Ice King says the brush is for princesses only, and it is shown that it has a dirty piece of Princess Bubblegum's hair stuck to it, which Ice King smells. He decides to look for a magic wishing eye online, but Gunter annoys Ice King. He decides and leaves to go to Wizard City to get a new wishing eye, ordering Gunter to "try not to break anything while [he is] gone." Gunter, in spite of Ice King, decides to break every bottle it can get their its hands on. It heads to the Ice King's recliner, where it is revealed that Gunter keeps its kitten offspring, and Ice King's demonic wishing eye.
Later, Finn wakes up to find a Gunter on him, and it zooms out to show the room filled with Gunters. Finn tries to make them go away, but they just mimic Finn. Jake gets angry and grows, knocking down all the Gunters but they grow too and attack Jake. Finn starts fighting them but they fall downstairs. The Gunters pin down Finn and Jake and start slapping them—one kicks Jake—and Finn screams "Ice King!" as he gets slapped.
The scene changes to Ice King flying to Wizard City. It is hidden by a fake cliff, and when Ice King says "Wizards rule," the fake cliff disappears. Inside the city, Ice King comes to a stop in front of a store. He reads the sign above that apparently has the wizard symbol for "magical items." He asks Huntress Wizard just to be sure and she replies, and Ice King complains that they should write it on the sign and protests "No More Symbols" and "No More Initiations!" Then Huntress Wizard asks if Ice King is trying to get himself killed then leaves. At this, Ice King mentions a Jay T. Doggzone and his advice of "swinging at every ball," meaning to try to hit on every woman. Ice King goes inside the store and inside is a hallway which leads to a room with a table and Bufo, Forest Wizard and Laser Wizard are talking there. After their conversation, they chant something as Ice King walks up to them. Ice King asks, "To keep what tight?" The three wizards get angry and Laser Wizard says it is a secret Ice King never should have heard. The three wizards walk up to him and attack him.
Meanwhile, Jake gets flattened by the Gunters and the real Gunter comes in with the kitten taped to its back and is wearing Ice King's demonic wishing eye and breaks two bottles. Finn asks where Ice King is, but Gunter just leaves, and the fake Gunters follow Gunter. Finn and Jake walk out of their house to find fake Gunters scattered all over the Grasslands. Finn wonders if the fake Gunters are everywhere, then Jake grabs a telescope. Jake, scared by what he saw, gets kicked by Finn and says "It's over. We've been conquered." Jake says everyone's been conquered by Gunter. Finn looks through the telescope and sees Gunter leading her army to the Candy Kingdom. Finn breaks the telescope and rides Jake to the Candy Kingdom, but Finn notices he is still in his pajamas and that he has to change.
Finn calls Princess Bubblegum and she is mad by the fact that there is an army of fake Gunters heading towards the Candy Kingdom. Princess Bubblegum says that Gunter has to get past the Banana Guards and the Gumball Guardians. Jake says that it will not work and Finn says that he has a plan and when he gets there he will do his plan as an addition to Princess Bubblegum's plan and ends the call. Finn tells Jake that he will not reveal his plan because he prefers to be mysterious, keeping all the ladies in a state of confusion; that way, he has "options in case Flame Princess doesn't work out." Finn says it is called "Future Farming" and he got it from Jake's book, Mind Games by Jay T. Doggzone. Jake tells Finn that it will mess up his brain and that he only kept the book for laughs because it is full of bad advice, but then tells Finn he can be mysterious, confusing him. Finn and Jake arrive and Finn climbs on the wall and Princess Bubblegum tells him the cavalry is standing by. Finn decides to rally some citizens, but then unicorn-shaped fake Gunters attack them. Then, Princess Bubblegum commands guards riding on candy horses to defend, but they fail. One Gumball Guardian tries to defend but is taken down by a giant Gunter made out of Gunters, and many more Gunters are coming. Princess Bubblegum taunts Gunter that it cannot break the wall, but it releases the cat and it shoots out lasers while being in an aura made out of energy and destroys the wall. Gunter flies to where the wall is and when the smoke clears up, Finn shows that his plan was to collect all the bottles in the land, as Gunter likes breaking bottles. The army follows and breaks more bottles, with glass flying everywhere.
Finn promises that they will not run out of bottles, but as Finn finished the sentence there are no more bottles left, and it shows that the bottles have been reduced to a pile of broken glass. Gunter calls its army to attack Finn, Jake, and Princess Bubblegum. Finn tries to attack Gunter, but Gunter uses the wishing eye to make its army spit out swords and attack. Princess Bubblegum says she has a third plan, which was to make bottles out of the broken glass (forever). Gunter comes in to tell the three that it will kill the Gumball Guardian if they do not give it any bottles. Princess Bubblegum tells it to wait, but Gunter decides to kill the Gumball Guardian, as Gunter taps the glass and makes a crack, Ice King, damaged, comes and sees Gunter with his wishing eye. Ice King then punishes Gunter by squirting water at it. Ice King commands it to remove the demonic wishing eye, and as Gunter does so, its army disappears and it walks away. Finn asks why Ice King is jacked up, and he replies that he got into some crazy wiz-biz at Wizard City and does not know how he survived. He is about to tell them, but (remembering it is a secret) only says, "Wizards only, fools. Keep it tight."
- When Ice King enters Wizard City, the viewer can see Brain Wizard is still a cat on the left corner. It seems that he has not broken the curse yet.
- When the pink kitten blows up the castle wall, a piece of debris is shaped like Tree Trunks.
- The official artwork of Jesse Moynihan shows Finn reading the book of Jay T. Doggzone, with a tense face. The back part of the book shows a photo of the author, who seems to be wearing a coat, a top hat and thick glasses.
- When Ice King searches for the Wizard Market on his computer, a list of his recent searches can be seen. See the first four images in the Screenshots section to view the list.
- Finn's communication device has improved since the episode "Go With Me."
- Finn calls Princess Bubblegum "Prubbs" toward the end of the episode.
- Ice King calls Gunter both a lady and "mister" in the same episode.
- When Finn was explaining Jake about his relations the title card music is heard.
- Ice King knows of Jay T. Doggzone's book existence too, and seems to be fond with it, as seen in "I Remember You."
- The articles Ice King's search shows are: blue potion, red potion, ancient staff, comfy booties and hog bristle comb.
- A few of the Gunther clones fly onto Finn's bed, indicating their abnormality, as real penguins cannot fly.
- Gunter hugging and rubbing his/her cat is seen again after beating him/her as the first boss in the Ice Kingdom in Break the Worm.
- Ice King says "What's your damage" to Gunter. This is a reference to the cult classic movie Heathers.
- A hidden wizard city is similar to Diagon Alley in Harry Potter.
- The Wizard sign used in the episode is similar to west side hand sign, where the fingers make the shape of a "W." It is also the inverse of Star Trek's "Live long and prosper" Vulcan hand gesture.
- Forest Wizard says, "Loose lips sink the ships," which is a reference to a WWII slogan which has been adopted as an idiom to mean that one should not talk carelessly because one never knows who may be listening.
- The oath that the wizards chant is similar to the Green Lantern Oath, though this was unintentional.
- Finn's Communication device somewhat may have a resemblance to a iPad or Samsung Galaxy Tab.
- When Ice King interrupts the other wizards, on the wall in gold letters is the word "April" written in the Theban alphabet. This alphabet has traditionally been used as a cipher by occult practitioners.
- One of the statues on the shelves behind the Secret Society greatly resembles an Emmy Award, only without the hollow globe on its hands. Emmy Awards are awarded for achievements in television.
- The images of items available on the online Wizard Market strongly resemble sprites from various video games; the "ancient staff" closely resembles the canes of Byrna and Somaria from The Legend of Zelda: A Link to the Past, and the "comfy booties" look similar to the pegasus shoes from the same game. The blue and red potions are also items in many The Legend of Zelda games, starting with the very first. The "magic wishing eye" resembles the Eyes of Ender from the video game Minecraft. The "hog bristle comb," however, may just be a call-back reference to the Ice King's brush "for princesses only."
- The title of the episode may be a reference to the popular game Don`t Starve`s addon, Reign of Giants.
- The transformation of the Kitten is very similar to the Goblin Force from the Marvel Universe.
- An Ice Penguin Monster from "King Worm" returns as a real character, but colored green.
- The idea of one of the Gunter's love for breaking bottles, first explored in "Still," is revisited.
- The Ice King's Demonic Wishing Eye, first shown in "When Wedding Bells Thaw," is utilized by Gunter.
- However, the original color of the Demonic wishing eye is red, but was changed to green in this episode.
- The place the title card depicts is the Candy Tavern. Finn, Jake, and Tree Trunks went there looking for "stolen" apples in "Apple Thief" and Jake went there with Mr. Pig in "Dream of Love."
- The name of the book "Mind Games" was mentioned again when Flame Princess told Cinnamon Bun that sometimes friends are "hard to understand" and that they are "just playing mind games." This may be due to Finn keeping all the ladies in confusion as stated in this episode.
- At one point in the episode where the penguins are on top of Finn and Jake, Finn's head was colored green.
- When the Ice King asks Huntress Wizard, Huntress Wizard's glove was missing, but it was shown when she responded.
- During the scene in which Finn explains that Gunter wants to smash the Gumball Guardian's head, there are two Gumball Guardians, but in the rest of the scene there is only one and they talk as if there is only one present.
- When Princess Bubblegum is preparing her defenses, she refers to her banana-guards as "calvary," rather than "cavalry." Calvary is the alleged site where Jesus was crucified. This is a common mistake in pronunciation.