Oona (Sofia the First)

Oona is a mermaid princess in episode 22 of season 1, and episode 1 of season 3 from the show Sofia the First. Oona is voiced by Kiernan Shipka.

Biography
Oona is the daughter of queen Emmaline and sister to Cora. In her debut appearance "The Floating Palace", Oona first meets Sofia when she comes to the surface to take a closer look at the Floating Palace. She accidently gets caught in a net until Sofia untangles her. The two of them soon become friends, and after Sofia's amulet gives her the power to become a mermaid, they dive into the ocean together.

Oona takes Sofia to her hideaway where they meet Sven and her big sister Cora, who heals her fin. Then, she and Sven give her a tour of the cove. When the Floating Palace appears at the surface and drops anchor, Cora swims up and demands that Oona returns home. Upon arriving, Oona and her mother have a debate on the Floating Palace's presence and discovers Sofia followed her home. Queen Emmaline tells them and Cora about the attack on her Kingdom and that that's why they're not supposed to spend too much time at the surface. When Plank proposes that Queen Emmaline move the ship out of the cove with her trident, Oona is against the plan because she knows Sofia's family is on the ship and how devastated her friend will be if they get hurt and can only watch in horror and listen in dismay as all this forces Sofia to admit that she's a human. When Plank starts acting negatively towards Sofia, Oona swims forward and angrily defends her by telling everyone how Sofia helped her when she was hurt and appeals to Cora who only says "All I saw was that you hurt your fin." to Oona's ire. Sven swims forward and says "I saw them. Sofia was helping Oona swim." After Queen Emmaline orders Sofia to leave and never come back, Oona swims away in disgust over how everyone acted toward Sofia and goes after her to comfort her. When Oona catches up to Sofia, she apologizes for how everyone acted and Sofia gives her a loving hug before sadly swimming back to her ship.

On the way back home, Oona is attacked by a sea monster who tries to steal the Mermaid Comb of Merroway Cove from her but fails thanks to the protective charm that's been placed on it. Oona swims back up to the surface and alerts Sofia. The monster captures her and takes her back to a boat and locks her in a cage. His attempts to break the charm protecting her comb draws the attention of Farley the seagull, who was sent by Sofia to find her, who tells Sofia. Sofia tries to save her by herself but the monster is too powerful. Sofia comes back with Cora who saves her with the power of the Mermaid Comb. She later witnesses her mother stop the storm and become friends with Sofia's family, to her delight.

She reappears in the first episode of the third season, "Cool Hand Fluke". She introduces Sofia to all her friends and reveals she's in a band. She plays a variation of a guitar. When her friend Fluke swims off on a dangerous quest, she joins Sofia to help keep Fluke safe. When hiding from the Mantacorn, she expressed her anger and disappointment in Fluke for risking their lives because he was jealous of the attention Sofia was getting. She later forgave him as he was allowed to perform with the band.