Heard a rumor that there's a shiny rayquaza avaliable if you do Mystery Gift. It's true I did it and it worked ^-^. Here's how --> Mystery Gift > Via Internet
The Rayquaza knows Dragon Ascent, Dragon Claw, Extreme Speed, and Dragon Dance. It's holding a Dragon Fang and it's in a red pokeball. This event ends August 31st 2015.
Hope it helped ^-^