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Pokémon fan site, Pokébeach, have invested a month of research into Pokémon Black/White’s code, and discovered a placeholder for an alternate form of the legendary Pokémon, Kyurem, who is the third member of the trio formed along with Black/White’s other two legendaries, Reshiram and Zekrom.
We don’t know what this second form looks like or what its abilities are; just that it exists, and that it will likely be used in the future. You can view a detailed explanation of how this second form was discovered at the link above.
The actual point of interest is that Pokébeach point out that Rotom, Shaymin, and Giratina, too, had placeholders for new forms in Pokémon Diamond/Pearl’s code, long before Pokémon Platinum was released.
