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 in canon.

While the Disney crossover film that serves as the Wreck-It Ralph squeal, Ralph Breaks the Internet, has online versions of the two known as "netizens", the inhabitants of the digital made world that lies within the real-life internet. Where they are two of the fourteen Disney Princesses that are from the expo-like Disney website, Oh My Disney.

Similarities and comparisons

 * They both have fathers who are the leaders of their people and who want to keep their daughters safe, as they fear of the dangers that they might find themselves in.
 * Ariel going anywhere near the surface world, Elsa losing control of her own powers.
 * They both appear as Disney Cameo characters in Ralph Breaks the Internet.
 * Are two of the Disney-based and owned characters in Once Upon A Time.
 * Are two for the Disney Princess characters who met Sora on their own home worlds in the Kingdom Hearts series. As well as both of them appearing in the same KH game.
 * Even though Ariel is a summon character in Kingdom Hearts III, while Elsa is revealed to be one of the new Princesses of Hearts. Along with Ariel being a very common character in the KH series, as for Elsa KHIII is where she makes her first official appearance in it.
 * Reside in castles that are close to the ocean.
 * Along with both of them being Disney Princesses that have two castles in their films.
 * Have lost their mothers.
 * Both have had a brief moment on a rock that sticks out above the ocean's waves.
 * Have had encountered with magical creatures that reside within the ocean.
 * Are two of the limit time characters in Disney Magic Kingdoms.
 * Have worn blue, sparkling dresses.
 * Are from two of the few Disney films that have become Broadway shows.
 * Have female siblings.

Fanon
While the exact origins of the ship is a mystery, as to when it started or what might have triggered the idea of shipping the two together, it could simply be due to fans who enjoy doing crossover, femslash ships that involve the Disney Princesses within the Disney fandom, or believe that a few of their similar traits can have the two get along with each other; as friends before moving onto lovers. Because Ralph Breaks the Internet is a canon Disney crossover, that has a version of the two know each other, the ship sometimes has them in the modern, casual style clothes that the netizen versions of them wear in the film.

Fandom
FAN FICTION

TUMBLR

Trivia

 * The Disney Princess group photo taking with Vanellope, in on of the later trailers of Ralph Breaks the Internet, netizen Elsa is seen above netizen Ariel.
 * While in the film itself, after Ariel emerges herself from the water that she swam through so it could take the shape of a spiral, she joins Elsa on Jasmine's magic carpet the moment she lands herself on it; before the Disney Queen uses her ice magic to freeze the watery spiral into a slid of ice. As netizen Pocahontas uses the wind to safely send Ralph to a soft bed to land on, Ariel has moved from behind netizen Jasmine to the frost of Elsa before she begins to sing.
 * Ariel has six older sisters, while Elsa only has one sister who is younger than her.
 * In Once Upon a Time, when Elsa punishes Blackbeard she unknowing traps Ariel in the bottle with the pirates.