I was EV training my Shroomish outside Dragonspiral Tower and suddenly... shiny Tranquill. The level 40 Shroomish (waiting to get Spore before I evolve it) is the only thing that won't 1HKO it, but luckily it had stun spore and false swipe.
I switch to Shroomish and have a long battle of false swiping the Tranquill while it roosts and healing Shroomish whenever it gets hit by Air Slash, which takes 2/3 of its health. Eventually the Tranquill is at 1HP and paralyzed, but it gets a critical and knocks out Shroomish. I switch to Serperior and prepare to toss Pokeballs at it. I'm picky about which balls my important Pokemon get, but luckily I had some luxury balls and catch it in one on the first try. It's naughty and has an IV of 30 in defense, so it's pretty decent.
I was half expecting a shiny soon, but from one of my Japanese ditto's masuda children, not a wild one.
Black: Keegan - 4127 4040 9358