The official Pokémon website has revealed that the Unova Starter Evolutions will also be distributed to English versions of Pokémon Omega Ruby or Pokémon Alpha Sapphire in North America and Europe. The Pokémon being distributed are the same ones that Japan got earlier in 2015.

Image	Information/Date(s)
Serperior (ジャローダ)	Distribution： Official Pokémon Website Event Period: January 22nd, 2015 until November 30th, 2015 Level: 50 Moves: Leaf Storm, Hold Back, Wring Out and Giga Drain Ability: Contrary Serial Number: POKEMON497
Emboar (エンブオー)	Distribution： Official Pokémon Website Event Period: January 29th, 2015 until November 30th, 2015 Level: 50 Moves: Flare Blitz, Hold Back, Head Smash and Take Down Ability: Reckless Serial Number: POKEMON500
Samurott (ダイケンキ)	Distribution： February Pokémon Trainer Club Event Period: February 5th, 2015 until November 30th, 2015 Level: 50 Moves: Razor Shell, Hold Back, Confide and Hydro Pump Ability: Shell Armor Serial Number: POKEMON503

Press Release - Three Stars of Unova!

Get Serperior, Emboar, and Samurott for your Pokémon Omega Ruby or Pokémon Alpha Sapphire game.

Add three more awesome Pokémon to the incredible list of Pokémon you can already get in Pokémon Omega Ruby and Pokémon Alpha Sapphire! The trio of Serperior, Emboar, and Samurott will all be available via secret codes you can get from either Pokemon.com or the February Pokémon Trainer Club newsletter. All of these Pokémon will have their Hidden Ability, so you'll definitely want to get all three.

Source: http://www.pokemon.com/us/pokemon-news/three-stars-of-unova/