Through a pair of unrelated promotions, you can claim two Mythical Pokemon right now.
For Pokemon Sun and Moon owners, Magearna is available–provided you’ve finished the main story. If you have, you can open up the in-game QR scanner and scan the code at the bottom of this post (you can also find it here). Once you’ve done that, head to Hau’oli City and talk to the deliveryman at the Antiquities of the Ages store to obtain your Pokemon.
If you haven’t yet completed the game, you don’t have to rush to do so. The Magearna code will stick around indefinitely, letting you collect it at your leisure.
Separate from that, you can also grab Meloetta for free right now in Pokemon X/Y and Alpha Sapphire/Omega Ruby. This comes as the final part of the Pokemon 20-year anniversary celebration that has seen a Mythical Pokemon given away every month dating back to February.
December’s freebie doesn’t require you to visit a store, as some of the past ones did. Simply choose the Receive Gift option from the main menu, receive it via internet, and you’ll then be able to collect a level 100 Meloetta at any in-game Pokemon Center. Step-by-step instructions are available here. Unlike the Magearna giveaway, you only have until December 24 to claim your Meloetta.
The QR code for Magearna