From Mental Floss magazine:
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. Thanks to Kevin Kosbab for becoming fluent in each language just to put the puzzle together. And for those of you who for some reason haven’t mastered these tongues, we’ve got a handy little word bank to help you. I don’t think I’ve said “word bank” since 3rd grade. Here’s the downloadable pdf, so you can print this sucker out. I’ll be back with the answers tomorrow. Good luck!