Adventure Time/Instances by character

] Fionna (previously spelled Fiona and also known as Fionna the Human) is an in-universe fictional character and the gender-swapped version of Finn who was created by the Ice King in his fan-fiction from a strange red glowing inspiration during Ice King's sleep. In the real world, she was created by series character designer Natasha Allegri in a series of webcomics and drawings. She and the other gender-swapped characters appeared occasionally in their own segment of the show. She is usually seen in the company of Cake, her own stretchy companion and also an adoptive sister. Fionna's nemesis is the Ice Queen. She used to have a crush on Prince Gumball and shows signs of attraction towards Marshall Lee, but she's also shown to have a past with Flame Prince. Ice King fantasizes about one day making her real and marrying her.

Adventure Time: Ice King Issue #3
Fionna and Cake are working out in a gym (in Ice King's fantasy), showing off their muscles after their work out.