SincereMasterpieces started making custom Krystal plushes last year and I think she will still do made-to-order Krystal plushes if you ask nicely.
Kreativjunkie shows off a commissioned life-size Krystal doll. I can't help, but compare it to a recent video game series.
Mancoin posted photos of Krystal cosplay and plushie.