
Longtime Adventure Time and Distant Lands executive producer Adam Muto executive produced the limited series and also served as the showrunner. It's more adult, so I think it's going to bring in new fans, and it's also going to serve the fans that we already have." Tonally, it is very much Adventure Time, but Fiona's older. The Adventure Time: Fionna and Cake limited series was developed specifically with the young adult demographic in mind, according to Suzanna Makkos, an executive for both Max and Adult Swim: "The Adventure Time fans have grown up and people are still coming in the bottom, and they're aging up", she noted in an interview with Comic Book Resources. The characters would make additional appearances in season five's " Bad Little Boy", season six's "The Prince Who Wanted Everything", season eight's "Five Short Tables", and season nine's "Fionna and Cake and Fionna". They debuted in season three's " Fionna and Cake", which functioned as both "a jab a huge celebration of, the feeling of being a fan" and "allowing something completely ridiculous to make your heart tighten". Reception to the gender-swapped characters was so positive that the Adventure Time producers decided to write the characters into the series. The idea for "Fionna the Human" and "Cake the Cat" evolved from drawings that Adventure Time character designer and storyboard revisionist Natasha Allegri had posted online during the show's earliest seasons. Speaking on the decision to order a new spin-off title, Billy Wee from HBO Max’s Comedy and Original Animation team said that they are “thrilled to partner with our friends at Cartoon Network Studios to continue innovating and expanding the Adventure Time universe with this world class team.The characters "Fionna the Human" and "Cake the Cat" were created by Natasha Allegri ( pictured) and worked into the third season episode " Fionna and Cake". All the while a powerful new antagonist determined to track them down and erase them from existence, lurks in the shadows.” – Press Release, via Warner Media. “Fionna and Cake – with the help of the former Ice King, Simon Petrikov – embark on a multiverse-hopping adventure and journey of self-discovery.

On August 17 th, 2021, Warner Media officially confirmed that HBO Max had ordered one full season for Fionna and Cake, consisting of 10 half-hour episodes. The response online was so positive that both Fionna and Cake appeared in the main series in six total episodes Fionna & Cake (season 3), Bad Little Boy (season 5), The Prince Who Wanted Everything (season 6) and Five Short Tables (season 8) and Fionna and Cake and Fionna (season 9).
