Nintendo just revealed another addition to the Mega Evolving roster of Pokémon X and Pokémon Y, and this one's a classic creature. Depending on which Mega Stone it holds, Charizard can now Mega Evolve into either Mega Charizard X or Mega Charizard Y, and you can see the Fire- and Dragon-type X, along with Y, in action below.
The Mega Charizard shown before was actually Mega Charizard Y, which can be Mega Evolved with Pokémon Y's Charizardite Y. Here's some official art of both X and Y:
Here's some more information on X straight from Nintendo:
Mega Charizard X is being introduced for the first time today. Players can obtain Charizardite X in Pokémon X and Mega Evolve Charizard into Mega Charizard X. Mega Charizard X’s Attack increases significantly and its Ability also changes to Tough Claws, which raises the power of moves that make direct contact. This Ability comes in handy when Mega Charizard X learns the Dragon-type move Dragon Tail which can force an opposing Pokémon to switch out during battle while also dealing damage.
Pokémon X and Pokémon Y hit Nintendo 3DS on October 12.