Zerg/For all maps:
(strategy name: mutaling rush)
Replay of strategy

1. Make 9 drones and scout with overlord.
2. Make and overlord.
3. Make 3 more drones and a spawning pool.
4. At the same time make an extractor and make 3 drones extract gas.
5. When spawning pool is finished, keep making lings and place them @ the entrance (this is your defence/counter attack in case opponent sucks).
6. When you have enough minerals and gas, make a spire and another hatchery right beside your other hatchery for faster mining.
7. As soon as spire is complete, keep making mutalisks as soon as you have enough gas, if you have more minerals than gas, keep making lings.
8. Scout for enemy by sending a few lings or a 1 mutalisk.
9. Upgrade if you have enough minerals.
10. Move all mutalisks just outside the enemies main base, farthest from the entrance.
11. The mutalisks are your main offence, the lings are the secondary offence that can be used for distraction or cleaning up the mess.
12. Attack the enemies workers with mutas and send all lings at front defence.