first season has a very subtle hint of adventure time
i had to look it up, and the the creator worked on it!
>working on the show, Allegri began drawing gender-swapped versions of the show's characters, including Fionna and Cake as her gender-swapped versions of Finn and Jake, and eventually these characters were featured in full episodes of Adventure Time. Since August 6, 2013, she also has written and illustrated Fionna and Cake comics for BOOM! Studios