She used to live in a non-magical and boring world with her cat, Cake, until she went through a portal that took her to a world completely different from hers, turning her from an ordinary girl into a girl.adventurous girl, and her ordinary cat, into a talking cat that has the power to stretch.Fionna and Cake go on adventures with Simon Petrikov, looking for a new crown for him. She is the female version of Finn Mertens and Cake female version of Jake the Dog. She is fearless and courageous