Talk:Nutcracker/@comment-25509684-20170521205756/@comment-34223508-20180509234214

the nickname is kinda japanenglish, as you can call nuts nattsu in japanese, and so they used that and cracker to make the name, since you usually say 'i'm eating some nuts', it's in plural so they probably just used that. also because the name is probably a reference to her habit of eating... eh. yes, which is usually referred to as nuts, in slang.

so basically they just combined the word nattsu with cracker and voilà. there you have the name.