Frostcest (also known as Icest) is one of the more unusual pairings, pairing up Jack Frost from Rise of the Guardians with an alternate incarnation of himself. Though not one of the most popular ships, this pairing has many followers.
In this pairing, different incarnations of Jack Frost are paired in a multitude of selfcest combinations.
Spirit of Winter, Guardian of Fun and Immortal Spirit. Jackson Overland Frost sacrificed his life to save his sister, and was chosen by the Man in the Moon, becoming the all-powerful force of nature you see before you. 300 hundred years later, he is chosen by Manny to become a Guardian and fight back the forces of darkness.
Jack Frost in his human years. A young quaker boy, Jackson Overland kept the whole village smiling with his fun and whimsy, the spark that made life worth living for all of the other children. Beloved brother, Jack is always there for his family, no matter what.
The female equivalent of Jack Frost. Jacquelin Frost lives the same life as her male counterpart, though sometimes is portrayed with a dress or skirt instead of a hoodie and pants. A common trait on most stories make it to where a mistake is made and the world knows her as "Jack Frost", blissfully unaware of her true name and gender.
Jackie is often paired up with Bunny, but this is not required.
A dark incarnation of Jack. Black Jack, also known as Jack Black, is the Prince of Nightmares and the ever-cretinous Boogeyman. Jack was once a regular human who was consummed by the darkness, becoming the ever powerful spirit of fear. While Pitch Black is a sly, composed being, Jack does little to hide his dark intentions, spreading fear and chaos with his mischief, his center corrupted to mask his sorrow and loneliness. In other scenarios, this incarnation of Jack was originally the Jack Frost we all know and love, but was corrupted by Pitch's power, often taking the arrow for Sandy when Pitch fires at him. This Jack is often portrayed wearing darker colors, with black hair, sick-tinted skin and glowing yellow eyes.
A dark incarnation of Jack. Icicle Jack is a form Jack takes should he allow his eternal lonelyness consume him. Where as Jack Frost is perky and extroverted, Icicle Jack is timid and introverted, his center nearly extinguished from his isolation. His hair and body is covered in spiky icicles like a fur coat, almost as if his humanity was slowly being consumed by his squandered power.
Jack's nordic incarnation. A commonly used variation of Jack when Hiccup is involved, Jokul Frosti is the Spirit of Winter known best in viking culture. While Jokul is often used for when Jack interacts with Hiccup, other scenarios like to paint Jokul Frosti as Hiccup himself if he became Jack Frost instead of Jackson Overland.
Note: Please add only ones that are part of the RotBTD fandom