Zerg (thing)

• Larva

  larva are the pre-unit of the Zerg. Each Hatchery, Lair, or Hive will pump these out on a fairly regular basis, with up to 3 larva around each building. The larva will then wander back and forth next to their Hatchery until they are ordered to mutate into a unit. This allows the Zerg to make a large number of units in a small amount of time, earning them the nickname of The Swarm.
  
  Vital Stats:
  Hit Points: 10
  Armor: 10 (they don't die quickly)

• Drone

  A Drone is the worker unit for the Zerg. They gather minerals and Vespene gas which the Zerg use to grow more powerful Warrior breeds.
  Drones are also necessary for the creation of all Zerg buildings. However, instead of constructing or warping in buildings like other races, a drone must morph itself into the building. This gives the Zerg a slight disadvantage, but one that is offset by the shorter training time.
  
  Vital Stats:
  Hit Points: 40
  Armor: 0
  Attack(Ground): 5
  Mineral Cost: 50

• Zergling (see excellent writeup there by mfk
  
• Hydralisk
  
• Lurker (Brood War only)

  This creature is morphed from a Hydralisk. It is unique in that it can attack only when burrowed underground. This makes it invisible to most units when attacking, but also makes it helpless when moving around.
  
  Its attack consists of shooting out a line of spines from its position, damaging all enemy ground units in that path. This makes them very good for dealing with masses of units, and ideal for base defense. The time it takes for them to set up, combined with their immobility when attacking, however, make them poor attackers, except with large numbers of backup.
  
  Vital stats:
  Hit Points: 125
  Armor: 1
  Attack (Ground): 20
  Mineral Cost: 50
  Gas Cost: 100

• Defiler

  A spell-casting unit in the. It has 3 special abilities, and no regular attack.
  
  Dark Swarm
  Energy cost: 100
  It is not necessary to research this spell. It acts to protect ground units from air attacks, and is often used later in the game in combination with cracklings.
  
  Plague
  Energy Cost: 150
  Mineral Cost: 200
  Vespene Cost: 200
  Truly devastating for all races. It affects all units in a small radius of the casting site, covering them in a red goo. This goo will leech away the unit's hit points until it wears off, the only has a few hp left, or Restoration is cast. As a side-effect, a cloaked unit will be visible as long as they are covered in the goo.
  
  Consume
  Mineral Cost: 100
  Vespene Cost: 200
  This spell will kill one of your own units, and raise the Defiler's energy by however many hit points the victim had. A common tactic is to keep a few zerglings handy for Consuming.
  
  Vital Stats
  Hit Points: 80
  Armor: 1
  Mineral Cost 50
  Gas Cost: 150

• Ultralisk

  With the addition of two new upgrades in Brood War, this unit rules the ground. Its strong attack and high hp is offset by the fact that it has no range and cannot attack air units. Still, sending a batch of these into an enemy's base is almost sure to do some damage.
  
  Upgrades
  
  Chitinous Plating
  Mineral Cost: 150
  Gas Cost: 150
  This upgrade adds a large amount to the Utralisks' armor. Combined with the normal zerg ground unit armor upgrade, this can make the Ultralisk virtually immune to many attacks.
  
  Anabolic Synthesis
  Mineral Cost: 200
  Gas Cost: 200
  This speeds up both the Ultralisks' attack and movement, effectively doubling damage dealt. A must-have for anybody planning an attack with Ultralisks.
  
  
  Vital Stats
  
  Hit Points: 400
  Armor: 1
  Attack (Ground): 20
  Mineral Cost: 200
  Gas Cost: 200
  

• Infested Terran

  Unlike other Zerg, the Infested Terran is not trained at a Hatchery. It is trained from any Infested Command Centers you manage to grab. It is a kamikaze ground unit, good for one very strong hit with splash damage.
  
  Vital Stats
  
  Hit Points: 60
  Armor: 0
  Attack (Ground, Splash, Suicide): 500
  Mineral Cost: 100
  Gas Cost: 50

• Overlord
  
• Mutalisk
  
• Guardian
  
• Devourer (Brood War only)
  
• Scourge
  
• Queen

The Queen has no attack, but does possess some handy special abilities. I have found it most useful as a scout, due both to its quick speed and the Parasite spell.

Queens have the following special abilities:

Spawn Broodlings
Energy: 150
Mineral Cost: 200
Gas Cost: 200
This will instantly kill any organic ground unit (which seems to include every Terran ground unit). Adding insult to injury, two units called Broodlings will replace the deceased. They are very weak, and even a worker unit can kill them. However, if the enemy has, say, a batch of Missile Turrets with one SCV guarding it, they can cause quite a bit of damage before their short life spans expire. Due to the fact that it requires a large amount of micromanaging, this spell is usually not used a lot.

Ensnare
Energy: 75
Mineral Cost: 100
Gas Cost: 100
Covers all units in a certaing radius of the target site with green goo, slowing their movement. Additionally, any cloaked units will be visible while goo covered.

Parasite
Energy: 75
Mineral Cost: 100
Gas Cost: 100
IMO, the most useful of the Queen's arsenal, although it deals no damage. This will allow you to see anything that unit can see. Especially handy if the unit is a detector or a transport. In multiplayer, players will usually send their parasited units on suicide missions. But if they don't notice...

Infest Command Center
When a Terran Command Center is sufficiently damaged, a Queen can fly in and infest it, putting it under the control of the Zerg player, and letting him/her train Infested Terrans. Very nice.


Vital Stats

Hit Points: 120
Armor: 0
Mineral Cost: 100
Gas Cost: 150

• The Overmind
  
• Zerg Cerebrates
  - Daggoth (Not yet noded)
  - Zasz (Not yet noded)
  
• Infested Kerrigan