Fionna's Dream of the Ice Prince has a distinct feel of a Magical Girl Anime; Ice Prince is even voiced by Robbie Daymond, known for the Role of Tuxedo Mask on Sailor Moon.
In Ep. 1, Fionna tells Cake to "Stop Acting Crazy!" In the exact same way Marceline tells the Ice King to in the Season 4 Episode "I Remember You."
First Adventure Time Series to be Rated TV-14. The original show was Rated TV-PG. Show not recommended for Children under 14.