One of the main changes of Mega Kangaskhan as opposed to its usual form is the participating of its baby in battle, who is no longer in its mother's pouch and fights alongside her in battle (though they are treated as a single Pokémon). This is represented by Mega Kangaskhan's new ability, Parental Bond, which allows Mega Kangaskhan to use two moves in a single turn.
It was first shown during the Opening Ceremonies of the 2013 Pokémon World Championships on August 10th. Curiously, it was not shown during the Closing Ceremonies along with the other Mega Evolutions.
Mega Kangaskhan's Evolutions
Mega Kangaskhan is the Mega Evolved form of Kangaskhan, evolving via Mega Evolution. It Mega Evolves during battle while its Mega Stone is held, along with whatever triggers Mega Evolution. The Mega Stone used to Mega Evolve Kangaskhan is currently unknown.
Pictures of Mega Kangaskhan
Here are all pictures of Mega Mawile that have been revealed. Click on any of the pictures for a larger size!