Hydralisk Drop This strategy is one of the most common Zerg strategy.  It is very effective against nearly all opponents.
		-Build  9 drones, make an overlord. -Make a pool, a creep colony, and and an extractor. -Build more drones, mine gas, build a hydralisk den, make another hatchery, and make your starting hatchery a lair. -Continue building more hatcheries and morphing Hydras. -Upgrade hydra speed, attack range, and all 3 overlord upgrades.  Also upgrade missile attacks and ground carapace. -Continue building mass hyrdas.  Don't forget to have spore colonies scattered around your base. -Build 12-24 mutalisks. -Build hydras until you can fill up 12 overlords (48 hydras), but keep some in your base. -Look for a weak spot in the side of your opponents base.  Go in with the mutalisks, and have your overlords drop every freakin' hydra into their base. -Ta da!