It's a mystery gift. Just cluck the giant box. You have until January to claim the event. Assuming you bougth the game legitimately?
Not to spam, but while I'm here. Mine came out bold natured, ups defense lowers attack, good if you like its fire side. Bad if you like the fighting type. Guess which one I want? I want a physical nature, I'm trading the X mega stone for charizard, or just each others torchic.