The SCV Slaughter
Start out by sending your overlord around the map to find your enemies base. Get your minerals going and build a spawning pool as soon as possible. Keep building overlords and drones while your spawning pool is being built. When you get at least 4 zerglings send them out to the enemies base. When you reach the base don't go after your enemies marines or zealots. Go after his probes and SCV's by using your zerglings speed to run around your enemies units. By the time your opponent kills your zerglings you will have caused his mining some damage. When your guys die it is no big deal because by now you have another 6 zerglings that are closing in on the base. Use the same tactic as before. By now your enemy knows what you are up to but is too weak to stop an all out rush. Send all of your guys, even drones to his base and take your poor opponent out.
The Zergling Kamakazii
There isn't much more I can tell you, the name is basically what you do. Build as many zerglings as possible and group them just outside your enemies base. When you have enough zerglings send them into your enemies base. Take out bunkers and cannons first, and then all the units nearby. After they are gone take out any sunken colonies if present.
Cool Zerg Attack Patterns By now you should know that the zerg are most effective when attacking from the air. This doesn't mean that they aren't good on the ground, but they tend to get chopped up by seige tanks and reavers. Here are a couple of manuevers that will ensure victory.
The Unprotected Entrance
This tactic requires that you build a sizeable force of air units. Build mutalisks, gaurdians, overlords, and scourges and group them just out of sight on the side of an enemy base. Now attack the main entrance to the base with some zerglings and hydras. Your enemy will respond to the attack and defend his base, moving most of his units to the hot spot. Now move in with your air units on the side of the enemies base, scourges first to eliminate any air opposition, and take out everything. Your enemy will be caught of guard and will scramble goliaths or dragoons against you. If you brought enough guadians along you should have no problem taking out these few units. Your enemy will be stuck with tanks that can't attack air units and you will inflict heavy losses.
The Suprise Flank
When most players attack your base they move in with marines followed by seige tanks, or zealots followed by reavers. To stop the attack you have to kill all of the marines first to get to the tank. This is extemely costly to your units because by the time they reach the tanks they have already been shelled at several times while they were caught up by marines. There is something you can do though to ruin this type of attack and insure your units survival. Burrow half of your units outside your base and the other half unborrowed at the entrance to it. Your enemy will walk in with tanks behind marines and start to attack. Unburrow your units behind the tanks and easily take them out. Now your units should have no problem taking out the marines or goliaths or whatever else is there.
Destroying the Enemy from Within
Evolve Overlords with transport ability and extra speed. Spawn 6 Hydralisks, 2 Queens, 4 drones and at least 6 mutalisks, Morph hydralisks into lurkers and drop them at a terran base, attack a command center or two while the mutalisks keep any air units busy. When the Command centers are in the red, infest them. Send in Mutalisk and Hydralisk re-enforcments. Create infested terrans from both Infested Command Centers and destroy the base from the inside out, eliminating the need to destroy the defenses first.------Ta-Da!
Sean's Starcraft Page