'Adventure Time': Fionna and Cake are back! -- EXCLUSIVE VIDEO

Fionna and Cake are back! On June 26, Cartoon Network’s hit fantasy romp Adventure Time will once again feature gender-swapped versions of main characters Finn and Jake. Madeleine Martin and Roz Ryan are set to reprise their alterna-universe lead roles as girl-with-cool-hat Fionna and stretchy-cat Cake on June 26.

The episode focuses on Lumpy Space Prince, the mustached, XY-chromosomed version of Lumpy Space Princess. EW is excited to exclusively share the first clip of the episode, complete with an impressive new voice for everyone’s favorite purple ball of fluff.

Can you guess the guest-star behind Lumpy Space Prince? Hint: He’s British. Double hint: He’s been in British things.

That’s Peter Serafinowicz, comedian and voiceover-guy extraordinaire! Things you’ve seen/heard him do recently: play Lord Covington on Parks & Recreation; say the funny line in the Guardians of the Galaxy trailer; voice a character in Dark Souls II. (If you think about it, Adventure Time is sort of like Dark Souls, except the complete opposite.)

The third Fionna and Cake episode airs on June 26, which coincidentally is the same date that people will start asking for a fourth Fionna and Cake episode.