When does Adventure Time: Fionna and Cake return?

The spin-off centers around Fionna Campbell, a young woman in a universe without magic who lives with her cat, Cake. The series debuted on August 31, 2023, and the second season premiered on October 23, 2025. In the first season, they have multiverse adventures with Simon Petrikov, a character who for most of Adventure Time had been known as the Ice King.