OMFG! I just beat muta-ling with hydra-lurk! Sorry, but this is incredibly exciting to me! Granted, he went 9 overpool and my 12 hatch/expo managed to hold out, but the fact that he made me stop mining and attack his creep/sunken right before I got my pool kind of offset that. Must go watch replay...
Edit: It was more of a macro win actually: he went 9pool speedlings into 1lair fast muta, while I went 3 hatch. He was still in the game though, until he decided to suicide his muta army against my hydra army (he lost ~18 mutas; if he hadn't done that, I would've had to move out cautiously, and he'd quickly get a macro advantage (he was already caught up to my 3hatch). If I moved out, I would've had to beat whatever he had (turned out to only be 3 sunk and a few ling) with only 8lurk and 20hydra since he could easily rip through my drones in seconds. If I chose to be cautious, I would've had to keep building hydras, and if he was smart and kept pumping out mutas while gaining map control I would've been horribly outmacroed and lost 1expo to 3expo)