StarCraft II: Wings of Liberty/Zerg buildings

Most zerg structures need to be on creep to stay alive. If any structure is not on the creep they will slowly die. Only Hatcheries, Overlords and Creep Tumors can generate creep. A drone must morph into the structure which turns the unit into a structure and it cannot be reversed once the structure is complete.

Hatchery
Spawns larva, creates creep and the primary zerg structure.

Lair
The second level of the Hatchery. Allows Hydralisks, mutalisks, corruptors and Infesters to be created. Also allows overlords to morph into overseers and various upgrades to be evolved.

Hive
The final transformation of the Hatechery. It has high health and allows Ultralisk caverns to be created.

Infested Command Center
This structure does not spawn suicide soldiers and it is only seen in the campaign.

Spawning Pool
It allows the spawning of Zerglings and offers upgrades such as increased movement.

Extractor
Cost 35 minerals and required to harvest any gas.

Evolution Chamber
Contains research upgrades for burrow (unlocks burrow), slime (Overlord), generate Creep (Overlord – this ability also increases Zerg buildings' Creep generation speed), and allows the Queen to produce Shriekers, increasing the range of the Sunken Cluster and Swarm Cluch abilities.

Hydralisk Den
This structure requires a Lair first and then you can spawn Hydralisks. Can upgrade the Hydralisks attack range.

Spire
Required to morph flyers and upgrade attack and defense. Takes 100 seconds to build.

Greater Spire
Required to morph the corrupter into brood lords and upgrade the air attacks and air armor to the next level. Takes 100 seconds to make a greater spire.

Ultralisk Cavern
Required to build the Ultralisk which can defeat Archons and Colossus.

Infestation Pit
Allows production of Infesters.

Infested Barracks
This structure is seen in the campaign only. It must be destroyed in mission Outbreak.

Infested Supply Depot
This structure is seen only in the campaign. It must be destroyed in mission Outbreak.

Infested Starport
Appears only in mission outbreak which must be destroyed or spawns of infested humans will do non-stop attacks.

Baneling Nest
It allows Zerglings to morph into Banelings and contains Baneling upgrades (increases speed as in make the banelings roll instead of crawl).

Roach Warren
It enables the spawning of Roaches, and contains Roach upgrades (heals roach faster and allow roaches to move underground).

Nydus Worm
A worm that pops out of the ground at any location and spawns creep around it. Whats worst is that it can deliver any zerg to any location including Ultralisks.

Spine crawler
A Mobile Anti Ground defense structure that is effective against armored units.

Spore Crawler
Has high health(400) and is best against air units. Can move to a different location. Detects stealth.

Infested Missile Turret
Even when infested it still sees cloaked units and fight jets.