The Demonic Wishing Eye looks like a giant medallion necklace with a red (green in "Reign of Gunters") eye at the center that the Ice King wears around his neck. He claims that his future wife may be marrying him to gain control of it in "When Wedding Bells Thaw." He keeps it on his neck near the Ghost pouch.
In "Reign of Gunters," it is revealed that the eye has the ability to create an unlimited supply of extremely powerful doppelgangers of the wearer; these doppelgangers are impossible to defeat but still have the will and mindset of the wearer. When Gunter wears it, the penguin doppelgangers gain abilities that allow them to easily take over Ooo, including physical manipulation of the form through face and size and the various transformation of form.
In the game Legends of Ooo, the Ice King is shown to have a different Demonic Wishing Eye that takes the form of a giant floating eyeball with green flames around it. It is able to translate wizard language into English.
- It is revealed that they can be bought at Wizard City.
- Its appearance differs from "When Wedding Bells Thaw" and "Reign of Gunters."
- It has 100% solid gold plating.
- It apparently gives the wearer "+5% critical hit."
- The Demonic Wishing Eye (The Eye itself) resembles the Eyes of Ender from the video game Minecraft
- Gunter wears it in the Adventure Time Game Creator.
- In the episode "Blenanas " it's revealed that the The Demonic Wishing Eye takes a piece of one's soul each time it is used.
- In the same episode, it's revealed that The Demonic Wishing Eye is inhabited by a creature named Wishy.