Lady Rainicorn

Lady Rainicorn, is a unicorn-rainbow hybrid (Rainicorn). She is Princess Bubblegum's flying unicorn and companion. She is also Jake's girlfriend. She sometimes follows Finn and Jake on their adventures. She does not speak English (except when equipped with the Universal Translator) and otherwise speaks Korean. Korean contains several loan words from European languages, so viewers may occasionally understand some of her speech. Jake is the only other being in the Land of Ooo, besides Lady's parents, that is shown to understand Korean, though Princess Bubblegum likely can because Lady is Princess Bubblegum's companion.

Appearance
Lady Rainicorn is a long unicorn-like creature. She has rainbow colored stripes along her body. She has big eyes, similar to Jake's. She also has a single, sharply-pointed horn, and a blonde mane and tail. Her mom has a long body like hers, unlike her father. This means that the length is inherited from her mom's side and/or only females have long bodies.

Abilities
Lady Rainicorn has the ability to fly and can use her horn to change the color of anything she wants. In the episode "My Two Favorite People," Lady Rainicorn explains to Finn that she can fly because her body can intercept beams of reflected light from the sun and "dance around" on them. In the same episode, she is shown to live in a stable in the Cotton Candy Forest. She can also speak a different language by using the Universal Translator. Also, Lady can stretch longer or shorter as you can see when she lands. She may have Stretchy Powers.

Personality and Traits
Lady Rainicorn is laid-back and likes to interact with Jake and Princess Bubblegum. She is considered Princess Bubblegum's companion, like Jake is Finn's companion. She's rarely sad or angry. In the Animated Short, she was seen crying and in the episode "My Two Favorite People," she becomes angry at Jake when he plays the viola with Tiffany. She doesn't speak Korean in the Animated Short; she only makes soft cooing sounds (or, near the beginning, hysterical screaming coos). However, Jake seems to understand what she says when he talks to her. She believes she is smarter than Jake. She may also have a fondness for Power Rings.

Jake
On the official website in Rainicorn's description, it says she is Jake's girlfriend and that they get along so well because of their common interest in the viola. This relationship began in the short when he and Lady Rainicorn were flirting and sharing interests. At the beginning of "Slumber Party Panic," she is shown being playfully chased by Jake, and later in the episode, she seems to very much enjoy playing "Seven Minutes in Heaven" (which is a mature game where two people are locked in a closet together to make out for 7 minutes) with him. In "My Two Favorite People," she recalls a time when she and Jake ran naked through a farmers field, causing Jake and herself to blush. This may indicate some level of intimacy in their relationship, even though neither actually wear clothes normally. In "My Two Favorite People," Jake admits that he wants to stay and fight with Finn, but he also wants to hang out with his girlfriend. Rainicorn later says she loves Jake "because he's an idiot" and that he makes her "feel like a genius." Jake can also understand Korean.

Princess Bubblegum
She is usually seen with Princess Bubblegum and nearby her in the Cotton Candy Forest in the Candy Kingdom. In the Animated Short, she shows great concern when the princess is abducted by Ice King. She is sometimes described as the princess' pet. Both of them were together in "What Have You Done?."

Finn
In the beginning of episode "My Two Favorite People," Rainicorn and Finn's relationship is awkward because, even though she can understand spoken English, Finn can't understand what she is saying, but they form a friendship when she helps Finn and Jake recover the Universal Translator at the bottom of the lake guarded by Lake Knights. When Jake puts the translator around Rainicorn's neck, Finn can understand her, and Finn is impressed by her ability to fight. They soon become good friends, without any awkward misunderstandings in communication.

Quotes
See Lady Rainicorn/Quotes

Trivia

 * In one room of the royal castle, there are two pictures of Lady Rainicorn on the wall: One of her upper half, and one of her lower half.
 * Two Rainicorns appeared in the Double Rainbow promo. It may be that they are both Lady Rainicorn somehow doubling herself using the light.
 * There are many episodes where Lady Rainicorn appears where she doesn't do so physically: she shows up in photographs owned by Jake such as in "Rainy Day Daydream," "What is Life?," and "The Eyes," and by Princess Bubblegum in "What Have You Done?"; as well as graffiti art in the title card for "Heat Signature" and in Jake's mind in "Mortal Folly," among other cameos.
 * Her original name was "Lady the Rainicorn."
 * Unlike her parents, Lady Rainicorn chooses to not wear a Universal Translator to speak to people of Ooo. Generally, her words are known and translated by those who understand her, like Jake.
 * Even though Lady Rainicorn looks friendly, she is actually a tough fighter, as shown when she saved Finn from Lake Knights.
 * In the animated short, she spoke in a type of gurgling language instead of in Korean.
 * In "The Real You," Princess Bubblegum is seen in the beginning with a yellow T-shirt with a red rainicorn on it, the rainicorn may be Lady.
 * Lady Rainicorn has a gender-swapped version of herself - Lord Monochromicorn.
 * On Natasha Allergi's formspring, she was asked if Lady Rainicorn and Jake will ever get married. She replied with, 'Maybe, i hope so!'

Major Appearances

 * "My Two Favorite People"
 * "Her Parents"
 * "Animated Short"

Minor Appearances

 * "Slumber Party Panic"
 * "The Enchiridion!"
 * "What Have You Done?"
 * "Power Animal"
 * "Go With Me"
 * "Video Makers"
 * "Mortal Folly"