Merillia is the life force of the ocean in the Barbie in A Mermaid Tale movies. The ability to create it is granted at exactly midday during the Changing of the Tides Ceremony to a member of the royal family, which takes place in the underwater city of Aquellia.
Merillia reflects its creator's emotions. If the creator is upset or depressed, then their Merillia becomes weaker overtime. Without a change, the Merillia slowly poisons the ocean. When Queen Calissa was imprisoned by Eris, her Merillia was not strong enough for the ocean to remain healthy. It only improved when Merliah released her.
Merliah later gains the power to make Merillia after performing the Changing of the Tides Ceremony.
| Barbie in A Mermaid Tale |
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 Quotes: "What makes you different just might be your greatest strength." | "It feels good to be a part of something bigger than yourself." Media: Barbie in A Mermaid Tale | Barbie in A Mermaid Tale 2 Characters: Alistair | Ally Mahoney | Ambassador Kattrin | Ambassador Mirabella | Ambassador Renata | Ambassador Selena | Break | Dreamfish | Eris | Fallon Casey | Georgie Majors | Hadley | Kayla | Kylie Morgan | Lipstick Fish | Merliah Summers | Pufferazzi | Queen Calissa | Remo | Rip | Snouts | Stargazers | Syrenka | Syrenka's Pet Fish | The Destinies | Xylie | Zuma Locations: Aquellia | Kayla and Xylie's Boutique | Malibu California, United States | Oceana | Sydney, Australia | Objects: Merliah's Necklace Songs: "Do The Mermaid" | "Queen of the Waves" | "Queen of the Waves (Eris Version)" | "Show Me Some Love" | "Summer Sunshine" | "Walking on Sunshine" Other: A Mermaid Tale Merchandise | A Mermaid Tale 2 Merchandise |