Kevin Kosbab of Mental_Floss became fluent in several synthetic languages in order to put together this crossword puzzle.

In order to solve this crossword puzzle, you’ll need to know a bit of Klingon, Elvish, Furbish, Esperanto and a handful of other constructed languages. In fact, all of the solutions are in constructed languages.

They helpfully include a “word bank” for those who haven’t mastered all of the tongues. (I mean, sure, everybody knows Klingon, but who ever heard of Esperanto?)

(via BoingBoing)