Pokémon Omega Ruby & Alpha Sapphire were, unsurprisingly, major hits for the 3DS in the Holiday season of late 2014, and as per tradition for the series there are consistent updates and extras to keep us playing. The Pokémon Company is now rolling out a code distribution in the West - that's already been completed in Japan - that'll bring three new 'Mon into your collections.
Serperior is first up and available now - you just input POKEMON497 in the game to pick it up; Emboar's code will be released on 29th January, with Samurott to follow on 5th February. These codes will be eligible until 30th November, with Emboar posted on the official Pokémon website and Samurott sent out to Pokémon Trainer Club Newsletter subscribers; they'll be all over the internet anyway, of course. Apparently the Serperior code is the same as it was in Japan, so the others may also follow that pattern.
So there you have it, free Pokémon; that's never a bad thing.