Arielsa

Arielsa is the femslash ship between Elsa and Ariel from the Disney fandom.

Canon
As Ariel and Elsa are from different series, they have never met. However, the two do appear in Ralph Breaks the Internet, and have a few brief interactions. Ariel joins Elsa on Jasmine's carpet, after emerging from the water spiral. Elsa then freeze's the water spiral, and Ariel will stand in front of Elsa when they reach Ralph. In Once Upon A Time, Elsa end up unknowingly trapping Ariel in a bottle along with Blackbeard's crew.

Ariel and Elsa both lost their mothers to ship wrecks, and have blue sparkly dresses created from magic. They also both have castles that are situated by the sea, and have a second castle in a completely different environment. Elsa has magical abilities, while The Little Mermaid tv series, did have Ariel gain powers for an episode. Just like Elsa, her powers get out of control but Ariel is able to get rid of them. The two were both able to bring two different types of people together, but end up having to leave their families in order to start anew in the other land. Before the two stared their new lives, they had felt that they didn't fully belong the one they were born into. Due to a hidden difference that they kept a secret from their families.

The two also have friendly personalities that allows them to become close with others and them with Elsa and Ariel. After a frightening event involving a family member, however, Elsa and Ariel locked themselves away within their castles, while keeping the reason for it a secret from the one they are protecting. When the truth of that magic related secret came out, both Ariel and Elsa lashed out in their own ways in which drove the person they were protecting away, until they made it right. Afterwards Elsa and Ariel brought down the walls that kept them apart from the outside world for so long, and celebrate the happy occasion with their families and people.

Fanon
Elsa and Ariel are shipped by a few fans, but are considered a rare pair. Artists and writers who enjoy Modern AU's will depict the two in the clothes they wore in Ralph Breaks the Internet. The ship became more popular after the release of the Frozen II trailer, where it showed Elsa running across the ocean. Fans wrote and drew Ariel coming upon Elsa as she attempts to cross, before helping Elsa to cross the Dark Sea, or has Ariel saving Elsa after she falls under the water.

A few fanfics have Ariel meeting Elsa as either a mermaid or human. Since Elsa's home castle sits next to the ocean and Ariel being fascinated by the surface world can lead to the mermaid coming across Elsa. Along with there being a fic that have Ariel save Elsa's life from drowning. Most of the Ariel!Human fanfics of Arielsa circle around modern AUs, as Elsa and Ariel meet and befriend one another in a high school setting. Because of the secrets they keep from the people around them, fans see Elsa and Ariel bonding the struggle that comes from it and how they could over come it, despite their fears.

On AO3, the ship has 11 fanfics in its Disney tag. While fanfiction.net has 12 in its Little Mermaid/Frozen category, with only 3 placed under pairing. Along with Arielsa having a small fanbase on Tumblr.

Fandom
FAN FICTION
 * Ariel/Elsa (Disney) tag on FanFiction.Net
 * Ariel/Elsa (Disney) tag on FanFiction.Net

TUMBLR

Trivia

 * The group photo taken with Vanellope, in the trailer for Ralph Breaks the Internet, Elsa is seen above Ariel.
 * The two are from two of the few Disney films that have become Broadway shows. As well as them being featured in the Disney on Ice show.
 * They are two of the limit time characters, with their own limit time clothing, in Disney Magic Kingdoms.
 * They are two of the Disney Princess characters who met Sora in their own home worlds in the Kingdom Hearts series, as well as both of them appearing in the same game, Kingdom Hearts III.
 * Elsa is the oldest sister while Ariel is the youngest.
 * They each have two castles.