Mega Crobat gets the ability Prankster, allowing its status moves to strike first, such as whirlwind, defog, mean look, taunt and confuse ray. Its speed stat raises to 180. The rest of its stats rise in a balanced manner. Its appearance changes to fit its new ability, as it can't be heard when flying now. Its wings set a bit longer and it gets blue markings on its body and a green tint on its underwings.
Stat boosts:
50 speed
15 attack
10 sp attack
15 sp defense
10 defense