Throughout Adventure Time, numerous imagination zones appear, sometimes interacting with the real world in unexpected ways. This article contains a list of these imaginary places.
Ice King's Imagination Zone
The Imagination Zone is a place visited by Ice King. First named in "What is Life?," it is a magical space where he can imagine anything he wants, usually beautiful princesses. He also imagines him and Neptr enjoying a sunset as father and son.
The Ice King can teleport himself and others into his Imagination Zone, although he also seems to go there involuntarily whenever Finn knocks him unconscious, as seen in "What is Life?" and "Prisoners of Love." It appears that Ice King cannot control who goes to the Imagination Zone, because Finn is able to go there by grabbing the hem of Ice King's robes. The Imagination Zone seems to behave like an actual physical place rather than just something imagined. In "Prisoners of Love" the Cosmic Owl appears in the Imagination Zone, calling Ice King a sociopath.
Neptr reminds Ice King of the Imagination Zone in "Mystery Dungeon" when he is desperate to meet Fionna after the failure of bringing his "Fionna and Cake" fanfictions to life. Within the zone, Fionna has the voice of Neptr.
Dark Magician's Brain World
Finn's Imagination Land
Finn's Imagination land is first shown in the episode "Freak City." Finn appears in it when the song "The Hero Boy Named Finn" begins. He appears to enter it by dreaming. It is later shown in the episode "Rainy Day Daydream," where Finn enters his mind by focusing on imagining. It is mostly blank, as Finn believes that imagination is for those who cannot face reality. There are three inhabitants: Bellamy Bug, Fairy, and Lyre Player.
Finn seems to know how to control it even though he never uses his imagination, but this could be simply thinking. It is also seen in "Goliad" when Goliad uses her psychic powers to enter Finn's mind. Finn tried to fight off what Princess Bubblegum said by thinking of many imaginative traps.
His imagination land appears again in "Frost and Fire" where he has a premonition dream about Flame Princess initiated by Ice King attacking her on their date. In the dream Flame Princess was seen burning Finn; he appears to enjoy it and it seems to hold a highly sexual context. The Cosmic Owl is seen whispering in the background and later in the episode is revealed to be saying "you blew it" to Finn, promptly afterward Flame Princess broke up with him.
Again in "The Lich" Finn experiences a premonition in which the Cosmic Owl is seen cackling over a television set. Billy is there within his crack with an old lady, the bear, the Enchiridion and the possessed snail.
Galaxy of Flavors
"The Other Tarts" begins with Princess Bubblegum describing a "Galaxy of Flavors" over a scene that resembles outer space filled with floating confections. Later, the Royal Tart Toter, despite being blind, deaf, and quite mad, perceives himself to be drifting off though the same galaxy. For some unknown reason, Lumpy Space Princess can be seen hitching a ride on a passing doughnut, though whether she is really there or just imagined is unknown.
Interestingly, title card designer Andy Ristaino confirmed that the title card of "Five Short Graybles" depicts the Galaxy of Flavors. Although the title card does not seem to fit within the episode's actual story, it appears to show Cuber inside a crystalline structure or spaceship, traversing the Galaxy of Flavors, which contains floating cupcakes, hot dogs, and sushi.
Jake's Croak Dream
Jake's croak dream (and croak dreams in general) might be affiliated with this phenomenon, being derived from the deeper parts of the mind like previous examples as well as associated with a sighting of the Cosmic Owl.
- The Imagination Zone is equivalent to Theosophy's Mental Plane where two minds can share dreams.
- The lyre player in Finn's imagination zone is also Sir Slicer's lyre player from "Blood Under the Skin."
- Ice King's Imagination Zone is darker green in its second appearance.