Ariel

For the episode, see Ariel.

Ariel is an optimistic, charming and romantic mermaid, who fell in love with a human after rescuing him from a shipwreck. Like all mermaids during a year's highest tide, Ariel was granted legs by the mythical sea goddess Ursula, and planned on using that to her advantage to gain her beloved prince's heart. However, not everything went according to plan, and Ariel had to go for many years as a mermaid, alone, and mute. But eventually, new opportunities arose for her to finally get her happy ending, and she's going to do all that it takes to ensure that she gets it.

Before the Curse
When Snow White almost drowns while she is on the run from Regina's guards, Ariel saves her just in time. Snow is shocked to discover that Ariel is a mermaid. When they reach shore, Ariel reveals that she's in love with a prince named Eric, whom she previously saved during a shipwreck. However, he doesn't know her true form. Ariel then turns her tail into legs, stating that it's a gift given by a sea goddess, Ursula. They then attend the ball, during which, Ariel dances with Eric, and he seems to like her back. He claims to have seen her before in his dreams and concludes it was a gift given by Ursula. He then asks Ariel to run away with him, but because of her secret, she seems unsure. He then gives her a choice to come or not. Ariel later goes out to the sea and attempts to summon Ursula, hoping for help. Regina, disguises herself as the goddess and gives the mermaid a way for her to keep her legs. Ariel gives Snow a bracelet she was given by Regina, but it turns her into a mermaid. The Evil Queen then shows up, revealing her true identity, and she forces Ariel to leave with her love, for if she doesn't, both she and Snow will suffer. Ariel however stabs Regina in the neck with a fork she stole and then escapes with Snow. When they reach safety, Snow tells Ariel to find her prince, which she does. However, when she attempts to call out for him, she discovers that Regina has taken her voice. She then swims away, heartbroken, for she shall never know true love. ("Ariel")

Season 3
When Regina, who's currently in Neverland and searching for her son, Henry, who's been kidnapped by the malevolent Peter Pan, stumbles upon Rumplestiltskin, she suggests that the two of them join forces in order to defeat the demon child. Rumple tells her that the only way to kill him is to die yourself, and so Regina suggests that they instead simply find a way to contain him long enough to get Henry back. Rumple reveals that he may have something back in his shop that could do just that, but has no way to cross realms in order to get there. Regina then leads him to a beach and uses a conch shell to summon the mute mermaid Ariel, who holds a grudge against the former Queen. Regina uses her magic to give Ariel her voice back and asks for her help, giving her the magical bracelet that will grant her legs and offering to make this transition permanent should Ariel retrieve a helpful magical item for them to use against Pan. The mermaid questions why she would help Regina, and the latter explains that the place she's sending Ariel (as mermaids are able to cross realms) has her beloved Prince Eric among its residents. Ariel wonders what this place is called, and Regina tells her, "Storybrooke." ("Ariel")

Rumple and Regina give Ariel a briefing on what she must do once in Storybrooke and Rumple gives her a shell, instructing her to give it to Belle as she'll know what to do with it. Ariel travels to Storybrooke and is met by the dwarfs. They take her to Belle, who is upset about Rumple's fate. Ariel brings news that he's alive and then gives her the shell. They later visit Rumple's shop together in order to figure out what it is. They soon find out that the shell projects a message recorded by Rumple and in it, he asks Belle to find an item in his shop. Realizing the chipped cup must be involved, Belle wonders what she could do with it. She puts it in the cabinet it once lived in, and once in place, a magical light appears, unlocking a hidden door. Belle opens the door and takes out a box, surprised at what she's seeing. Ariel wonders what it is, so Belle explains that it's Pandora's Box. However, before they can leave, the two unwelcome visitors arrive with guns and tie the two girls up. They take the box off them and leave to destroy it, so it can't be used against Pan. The girls manage to escape their binds by turning Ariel into a mermaid again, and once free, they head to the mines and stop the men from destroying the item. They become upset and state they were only trying to save their sister, whom Pan has prisoner. Their sister is Wendy Darling. Later on, Ariel swims back to Neverland to deliver Pandora's Box, and in return, she is given full control over her legs and tail. She then heads back to Storybrooke.

Ariel, who's been dolled up by Belle, struggles to walk in heels as her new best friend aids her towards her true love, Prince Eric, who, in Storybrooke, is the local fishmonger. The mermaid is a tad offended when she sees him chopping fish by the docks, thinking it means he may not like her, but Belle convinces Ariel to go to him, and she obliges. Eric soon notices her, remembering her from their brief encounter back in the Enchanted Forest, and after he removes his gloves he immediately grabs her and passionately kisses her, much to Ariel's, and an onlooking Belle's, delight. Before long, a noise is heard in the sky as the Jolly Roger tears through the protection spell and heads downwards, containing all those who journeyed to Neverland to save Henry, and some additions. Belle is ecstatic that Rumple has returned to town, and before long, the ship docks, allowing Ariel to reunite with old friends such as Snow White. The mermaid then presumably leaves with Eric and begins staying with him, the two of them happy to have been reunited with one another.

After Regina undoes the Dark Curse in order a vanquish a threat brought on by Peter Pan, everyone in Storybrooke is transported back to the Enchanted Forest, including Ariel and Eric. However, Eric is soon kidnapped by a band of vicious pirates aboard a ship known as the Jolly Roger, and so she assumes his captor is Captain Hook. She ambushes Hook in an ally one night and holds a dagger to his throat - one that one of Eric's men found in the armory of the ship and used to escape - but it soon become apparent that Hook hasn't seen the Jolly Roger since the curse undid. He inspects the dagger and notices the signature of Black Beard, deciding to pursue the notorious pirate and claim his ship back, and Ariel tags along, wanting to be reunited with her prince. On the way, the cloak given to her by Eric gets caught in a bush and Hook tears it with his hook to break her free, much to her dismay. She begins berating him, but he doesn't care, and she goes on to admit how surprised she was to hear that Hook might have been involved in Eric's kidnapping due to all the stories she heard of him being a hero helping Snow White reunite with her family in Neverland; Hook denies these claims, making clear that he's a pirate and nothing more. They soon arrive at the ship, and as Hook and Black Beard sword fight, Ariel searches for Eric, but he's nowhere to be found. She resurfaces just as Black Beard is about to be killed but manages to stop Hook from doing so, pointing out that only he knows where Eric is and needs to tell them. Black Beard laughs when he realizes this entire event was a rescue mission, mocking Hook for having gone soft, and reveals that Eric has been stranded on a deserted island. He refuses to tell them where unless Hook gives up the Jolly Roger, but he refuses, making Black Beard walk the plank and get eaten by sharks. Ariel is dismayed, now unable to find out the whereabouts of her true love, and removes the enchanted bracelet which grants her legs and swims away into the ocean, in hopes of locating Eric by herself. She soon finds him on Hangman's Island where the two of them joyously reunite. When Zelena, the Wicked Witch of the West, casts a new curse, Ariel and Eric are outside its proximity and so are able to remain in the Enchanted Forest, living out their happy ending with one another.

In Storybrooke, Zelena uses her magic to disguise herself as Ariel, pretending to wash up on the shore where she's found by David and Mary Margaret, who take her to Granny's Diner after she explains that she's been searching every known realm for Prince Eric, who's been missing ever since the new curse hit. They ask Hook, who's memories are still in tact, if he came across Eric during the missing year, but he lies and says that he did not, going on to escort "Ariel" to Mr. Gold's shop in the hopes of finding one of Eric's possessions and using a locator spell to track him. Hook finds his cloak, which they then follow to the docks, watching as it's sucked under water. They deduce that he drowned, and "Ariel" is devastated, leading Hook to admit how he betrayed her during the missing year. She appears disgusted, and makes him swear he's sorry on the name of the woman he loves, and he swears on Emma Swan. This then allows her to curse his lips, before revealing herself as Zelena and informing him of Ariel's true fate, as well as explaining that the next time his lips touch Emma Swan's, her magic will be drained. Emma, who's being trained in magic by Regina, hears of where Ariel is and uses mirror magic to check up on her, seeing her and her prince kissing passionately on a beach, very happy together.

Gallery
Gallery of photographic stills released to promote the character.