What Language Does Lady Rainicorn From Adventure Time Speak?

Cartoon Network's critically-acclaimed animated series Adventure Time ran for ten seasons from 2010 to 2018. The show is set in the mythical land of Ooo and centered around two best friends, Jake the dog and Finn the human, voiced by John DiMaggio and Jeremy Shada, respectively. The sword-wielding boy and his shapeshifting sidekick venture all around this fantastical world, going on dangerous and exciting adventures and meeting plenty of strange creatures. Some supporting characters that regularly appear throughout the series include BMO, the sentient video game console system and friend of Finn and Jake, Princess Bubblegum who rules the Candy Kingdom, Marceline the vampire queen, and Jake's love, Lady Rainicorn.

As her name would suggest, Lady Rainicorn is a long, rainbow-colored unicorn creature, very reminiscent of Haku in his dragon form from the Studio Ghibli film Spirited Away. While she has a strong romantic relationship with Jake, Lady Rainicorn is also very close to Princess Bubblegum, and she is one of her official royal steeds. It's unclear if Lady Rainicorn and Jake are married or not, but they are longtime partners and parents to five kids — Charlie, Viola, Kim Kil Whan, T.V., and Jake Jr. One of Lady Rainicorn's most notable characteristics is that she doesn't speak English, and without Jake serving as translator — or using a translation device like she does in the episode "My Two Favorite People" — Finn isn't able to understand her.

So what language does Lady Rainicorn speak in Adventure Time?

Lady Rainicorn always speaks in Korean. Although they never speak the language themselves, Jake and the couple's kids all appear to be fluent in Korean as well. They can understand Lady Rainicorn perfectly and respond to her questions and statements in English. In Adventure Time, Lady Rainicorn is voiced by Niki Yang, who is also the voice of BMO. She originally worked as a storyboard artist for Adventure Time and the series was her first real voice acting job. Overall, Lady Rainicorn also appears to follow many aspects of traditional Korean culture, as Adventure Time features written Korean, also known as Hangul, as well as Korean cuisine and other cultural details.

The team behind Adventure Time originally just wanted Lady Rainicorn to speak a language that casual viewers wouldn't necessarily recognize. Korean might've been settled on because of convenience or as a way to honor the show's connection to Korea, as many of the storyboard artists were Korean and the series was animated there. According to an interview The Daily Beast had with series producer Kent Osborne, Adventure Time would go through initial plot planning before being laid out on storyboards to be approved by the network. Then "there's layout design and background design and color design going on [...] to prepare for sending it overseas to Korea." The American team worked with Rough Draft Studios in Seoul for the animation, the production company behind other classic cartoons like The Simpsons, The Powerpuff Girls, and more.

Niki Yang mentioned in an article with IndieWire that she got a lot of responses from Korean viewers about their surprise and awe at the show including Korean. She said, "So many people found me somehow – they are second generation here, or their parents are speaking Korean, so they kind of know Korean. It was a joy that as they were watching the TV, Korean just popped up! They write emails to me and just enjoy the moment. By now, I think Adventure Time is getting popular even in Korea, so it's amazing." 

In another interview with Key Frame Magazine, Yang elaborated on the feedback she's gotten and why she believes Lady Rainicorn speaking Korean is so important. She shared that many second generation Koreans have "never seen someone from their generation doing something creative, like being a comedian or voice actor. They have to see these people exist. It's important." While Yang continues to do voice work, she's also moved on to directing, with Clarence and Summer Camp Island.

For anyone curious, Korean viewers on Reddit said that Lady Rainicorn still speaks Korean in the Korean version, but it's a different voice actor and the audio is distorted. Another commenter stated that the Dutch version of Lady Rainicorn is "just gibberish." Lady Rainicorn appears in many episodes throughout the eight years Adventure Times was airing, and she has an extensive character arc revolving around her relationships with Jake, their children, and Princess Bubblegum. Clearly, Lady Rainicorn is more than just an animated character, and she continues to impact people around the world long after Adventure Time aired its last episode.