Fionna

Fionna (previously named Fiona) is the gender-swapped version of finn, created by series designer Natasha Allegri. She is usually seen in the company of her own stretchy companion, Cake, who is the gender and species-swapped version of Jake. Fionna's enemy is the gender-swapped version of Ice King, the Ice Queen. It was revealed on April 6, 2011 that the working title of the sixth episode in season three is "Adventure Time with Fionna and Cake."

Appearance
She wears an outfit similar to Finn's: a rabbit-themed hood (opposing Finn's bear-themed hood), exposed locks of blonde hair. Unlike Finn, she has her neck exposed. She also has a sky blue shirt with longer sleeves than Finn's, and a dark blue skirt.She has a lighter shade of blue than Finn's clothing, the same green backpack, athletic socks that have two blue stripes at the top, and Mary Jane shoes on her feet. In the Ice Kingdom, she wears a yellow sweater. She also wears reddish orange pajamas.

Trivia

 * Her name was officially changed from "Fiona" to "Fionna," presumably to make it more similar to Finn's name. Pronounciation, however, remains unchanged according to Natasha Allegri.
 * Like Finn and his crush on Princess Bubblegum, it is revealed in many portraits posted that Fionna has a crush on Prince Gumball.
 * In some portraits posted, Fionna, similar to the way Finn has missing teeth, she has buck teeth like a rabbit. In the actual episode, though, these are absent.
 * Revealed on Natasha Allegri's formspring account, the dress she designed for Fionna is based off Princess Serenity's dress from the anime, Sailor Moon. This may also be the inspiration for Fionna's rabbit-themed hood, Sailor Moon's protagonist is named "Usagi," which is Japanese for "rabbit."
 * As shown on the Adventure Time with Fionna and Cake preview, Fionna kicks with her right foot.
 * Fionna uses more complex words like "predatoring", though it could just be her making up words, like Finn does.