Start off by building workers and a extractor, when you get about 8 workers build an overlord and two creep colonys. Build more workers and a spawning pool then turn the creep colonys in to sunken colonys so you can have defenses. Build more workers and about 6 zerglings build two more sunken colonys and a evolution chamber. Then you build a couple more workers and a hydralisk den then upgrade to lair. Then a couple of spore colonys, hydralisk, overlords and two spires. When the spires are building, build more workers and more hydralisk and an other hatchery. Then build more hydralisks a queens nest and more workers and hydralisks. Now you should have alot of hydralisks and workers, now get alot of mutalisks and upgrade to hive. When the hive is upgraded get a greater spire and get some guardians and devourers leave some mutalisks. When you get around 12 guardians and devourers attack the enemy with them and build more at your base. If the enemy counter attacks you will have the hydralisks the strategy should work if it don't then you will have plenty of minerals to build your base more. *You should upgrade all your air units and some in the evolution chamber, you should also build a couple queens with there ensnare you can easily kill air units.

CreepColony's Opinion: You can also load a bunch of overlords with hydralisks, and drop them on your opponent while your air units are attacking.