User blog comment:HazelQuill7445/Awesome fan art/@comment-28288412-20161021183331/@comment-4010415-20161022082653

Yeah..

Original Japanese = Unknown sex

English manga = Female

English anime = Male

I think there's even a moment where Patty asks if Crona seems kinda like herself and Liz, and Liz goes on this total anime-esque thing about their past, and Patty was like "No, I mean, don't you think Crona kinda looks like us?" as a joke that Crona seems feminine but may be male.

The insistence on keeping them ambiguous may also be why Crona's underwear has never been shown despite their robes getting pulled up once.

Though, I read that the author made Crona ambiguous to give the fans a character who they could ship with other characters and decide for themselves if it was straight or same-sex.