“Adventure Time: Fionna and Cake,” which premiered Aug. 31 on Max, is a spinoff of the playfully subversive Cartoon Network series that aired from 2010 to 2018.

The “Adventure Time” universe is expanding, with HBO Max ordering a new half-hour series about Fionna and Cake. In the 10-episode series, Fionna and Cake – with the help of the former Ice ...

HBO Max has ordered Adventure Time: Fionna & Cake straight to series. The new show will follow Fionna and her magical cat Cake in a brand new, half-hour animated series.