A Starcraft 2 Zerg vs Terran matchup can prove to be a very interesting proposition. Pairing up the most aggressive race in the game with the most defensive is definitely going to produce some sparks.

At least as the game starts, you can expect your Terran opponent to wall himself in and build a solid defense. He knows he is the weakest at this stage of the game. He also knows that the Zerg are extremely dangerous at this stage of the game.

Your opponent will tend to dig in and block off his ramp with Supply Depots and Barracks, waiting to tech up to Siege Tanks and Marauders. This is usually done to allow them to survive for long enough to tech up to Banshees. Here are a couple of things you can do to stop him.

The Baneling/Roach Rush
This type of build can prove to be very destructive against a Terran who's going for Siege Tanks and/or Banshees.

This build makes use of a second Hatchery once you reach thirteen supply and then a Roach Warren at sixteen. Immediately after you order the Roach Warren start making a Queen as quickly as resources permit it. After the Queen is done create two pairs of Zerglings and then start your Baneling Nest once you reach nineteen supply; as the Nest is being built start making five Roaches.

You should morph the four Zerglings into Banelings somewhere close to the Terran's base. It should however be out of plain sight. Use your Banelings to create a gap in his wall - ideally taking out a Supply Depot should suffice so that you can get your Roaches in.

If the wall-in is not made up of Supply Depots or add-ons and is instead made up of a Barracks and a Factory then this tactic will not work. In this case you might want to increase your number of Roaches if you see him making Hellions. However, if you see him making Marauders then return to base and dig in a bit so that you can transition to Mutalisks.

The 1 Base Mutalisk Build
The goal of this build tactic is to sacrifice expanding in favor of getting a Spire down very quickly. This type of tactic can create extensive economic damage to a Terran player's economy. Ideally, your Spire isn't scouted and there are no air defenses up.

There are a few things that you have to do in preparation of this tactic. One of them being that you will want to Metabolic Boost your Zerglings from the get-go. They will act as your initial scouts and defense. Keep in mind to build a couple of Overlords beforehand because a Mutalisk will take up two supply.

A great positioning tip would be to place your Spire somewhere between your main base and your natural expansion so as to minimize the chances of it being scanned. Use an Overlord to drop some Creep wherever that place may be and once the Lair is done, start making your Spire.

Start harassing the Terran's supply line as soon as you have at least five Mutalisks. You should micromanage them carefully as he might have some anti-air defenses up. Don't be all gung-ho on attacking them without regards to the safety of your units. You can always pull back and wait to spawn a few more.