Mermaid Beauty

Mermaid Beauty is the femslash ship between Ariel and Belle from the Once Upon A Time and Disney fandoms.

Dark Hollow
Ariel meets Belle when Mr. Gold and Regina Mills sends the mermaid to Storybrooke, with the task of finding her so they could find and retrieve a powerful item for them. Once Ariel arrives in Storybrooke, she asks one of its locals where she can find Belle before Leroy bring the mermaid to her at the diner. After Belle hears that Rumple is the one who sent Ariel to her, she gives Belle the enchanted sand dollar that Mr. Gold asked Ariel to give to Belle as a staring point to want he needs the two to find, before Belle and Ariel head immediately to the pawn shop so they could look for this mysterious object that will Mr. Gold and Regina defeat Pan without killing him.

After Ariel changes into more modern clothes while Belle uncovers Rumpel's hidden message, they begin to search through the shop. As they search up and low Ariel tells Belle a bit about Eric and how she felt that it didn't work out between them until Belle shares her thoughts and feelings she has for Mr. Gold and that she shouldn't give up on the love she has for Eric or the hope of her being reunited with him. Once they found Pandora's Box, Belle shares what she knows about it with Ariel and that she is surprised to learn that Mr. Gold has such a powerful box in their shop.

Before the two women could talk about bringing the box back to Neverland, two strangers walk into the back room with guns that they use to hold both Belle and Ariel at gunpoint, before tying them up in two chairs that back-to-back to each other; and for Ariel's safety Belle tell her that they should obey their demeaned, much to Ariel's confusion. After being interrogate by them about the box they leave Belle and Ariel, without untying them, the women began to struggle in hopes that they be able to break free of their binds and as Belle begins to lose faith in herself and apologizes to Ariel about her never being able to be with Eric, until the mermaid tells her about the bracelet she is wearing and how it can help them get free. Once Belle removes it from her new friend's wrist Ariel's legs transform back into their natural tail, and the two women fall over; after Ariel is loose enough for her to untie herself before help Belle; Ariel puts the bracelet back on so they could immediately leave the shop and retrieve the box.

Once they despatched from the two men, who only wanted to keep their sister safe since Pan is holding her captive, and simplify after they got Pandora's Box back, Ariel and Belle head to Storybrooke's shoreline where they say goodbye to each other. Ariel promises Belle that she'll deliver her message to Mr. Gold before taking off the bracelet and leaves to make her way back to Neverland.

The Jolly Roger
Their paths later crossed with each others again when Ariel needed help to find Eric in Storybrooke. Belle is happy to see Ariel again and the two hug each other before explaining her reasons as to why she has returned to Storybrooke before they begin to look through the shop to see if there is anything that could have them find him.

Fanon
While the ship is commonly focused on OUaT's version of the two, there are fans who use ship and its commonly used title with Disney's versions of them within the Disney Princess part of the Disney fandom, since the ABC television series has its own versions of the Disney characters and has a few traits from its series; and it being the live-action show that helped to trigger the ship or had helped to make it popular in both fandoms.

Because Ralph Breaks the Internet is a canon Disney crossover that has a version of the two know each other, like their Once counterparts do in the Once Upon A Time series, fans sometimes place Ariel and Belle in the modern style clothes that their netizen counterparts wear for Modern AUs and crossovers.

On AO3, the OUaT side of Mermaid Beauty have over 17 fanfic, while the Disney crossover side of it has 15.

Fandom
FAN FICTION
 * Ariel/Belle (Disney) tag on FanFiction.net
 * Ariel/Belle (Sofia the First) on FanFiction.Net
 * Ariel/Belle (Kingdom Hearts) on FanFiction.Net
 * Ariel/Lacey (Once Upon A Time) on FanFiction.Net
 * Ariel/Belle (Kingdom Hearts) on FanFiction.Net
 * Ariel/Lacey (Once Upon A Time) on FanFiction.Net

DEVIANTART

TUMBLR

Trivia

 * In the Disney film, Ralph Breaks the Internet, Belle and Ariel appear as online versions of themselves 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.
 * In the film, Belle is seen sitting close to Ariel when the princesses are in their new comfy, modern style clothes; and Ariel taps Belle on the shoulder as she talks about her new clothes with the other princesses while Belle smiles at Ariel as she speaks.
 * Both Belle and Ariel appear in the Disney Junior series show, Sofia the First, when the Amulet of Avalor summoned them to aid Sofia.
 * They are two of the common Disney Princess characters in the Kingdom Hearts series, as they both appear in the first game of the series saga and Kingdom Hearts II. Along with memory versions of the two in Kingdom Hearts: Chain of Memories.
 * As well as Ariel reappearing as a summon character in Kingdom Hearts III.
 * Are from two of the few Disney films to become Broadway shows.
 * They are two of the limit time characters in Disney Magic Kingdoms.

Variations

 * Desert Mermaid Beauty refers to the ship between Ariel, Belle and Jasmine