Regigigas for the Sun games, and Heatron for the Moon games.
NintendObserver’s select content on the Pokémon Trainer Club.
Introducing the new Pokémon Trainer Club Collectible Gallery feature.
ICYMI, Mew will be available once again through the Pokémon Trainer Club newsletter.
Wait. So Pokémon is actually officially encouraging people to spam Sheer Cold and Substitute.
Only available through Pokémon Trainer Club.
Each of them has its Hidden Ability.
You have to manually enter the Pokémon you own so, I don't really think I'd recommend that.