StarCraft II: Wings of Liberty/Zerg units

Returning Zerg Units
Old units came back only some of them changed

Drone
In StarCraft II, Drones are no longer required to build defensive structures, such a role having been taken over by the Queen.

Hydralisk


Hydralisks will be featured in StarCraft II.

Their appearance have changed slightly in StarCraft II. The most notable difference is their scythes, which now boast more spikes than in StarCraft. Their face is also slightly different from what it was before.

The Hydralisk maintains the ability to morph into a Lurker.

The Hydralisk is protected by light armor.

Larva
The Larva reappears in StarCraft II. It is protected by light armor.

It can produce a large variety of units: Drone, Overlord, Zergling, Roach, Hydralisk, Nydus Worm, Infestor, Mutalisk, Corrupter, and Ultralisk.

Mutalisk
The Mutalisk made an appearance in the WWI gameplay demonstration and have been confirmed as playable units.

Game Unit

In StarCraft II, its attack will still be able to strike multiple targets, bouncing to strike up to two additional targets as before.

It is protected by light armor.

Abilities


 * Swarm Guardian Morph

The Mutalisk can morph into a Swarm Guardian.

Overlord
The Overlord has made an appearance in StarCraft II. It functions in a manner similar to its StarCraft I predecessor (a flying Control-producing unit).

Queen
The Queen appears in StarCraft II, though is a vastly different unit from its predecessor, first notably now walking on the ground. It functions as a Hive Warden.

Ultralisk


Featured in some game builds; now has 4 scythes instead of 2.

Zergling
Zerglings have evolved, affecting such things as their appearance. They have small wings but cannot use them to fly.

They can morph into banelings and burrow.

New Zerg Units
Here are totally different and new Zerg units that changes the Zerg 100%

Baneling
The Baneling is a wheel-shaped explosive Zerg strain descended from the Zergling. Banelings roll around the battlefield and kill opponents with a low-damage suicide attack caused by their explosive body chemistry.

Banelings are strong against melee units but are weak against ranged weapons due to their low hit points. A Nest is required to spawn them, which also provides upgrades.

ITs' splash damage does not hurt friends.

Corrupter
Attacks air units and "corrupts" them rather than destroying them.

Overview

The Corrupter attacks air units. Instead of destroying them, however, it "corrupts" them, possessing the enemy units. It can cause a large group of units to fight each other, quickly turning the tide of a battle.

The Corrupter is treated as an armored unit. It is unlocked by the Spire.

Infested Marine
The Infested Marine is a different unit than StarCraft's Infested Terran; they're essentially regular Marines with Zerg appendages, so instead of detonating themselves, they shoot while moving a bit slower than the regular Marine.

The Infested Marine, armed with gauss flayer, can be quickly produced in large numbers from Infested Barracks. The Infestor, a Zerg ground unit, can infest Barracks (and possibly other structures), which then disgorge Infested Marines. Infested Marines don't do much damage, but make for good distractions against an enemy.

Infestor


The Infestor is a replacement for the Defiler for no reason, retaining its predecessor's Dark Swarm ability. It cannot attack but is capable of moving while burrowed.

Nydus Worm
Can be used to transport small units such as Zerglings underground.

Additional Notes

The Nydus Worm is a StarCraft II Zerg transport unit used to transport large numbers of small units, such as up to fifteen Zerglings.

It can transform itself into a Nydus Canal, at which point units can enter it and "accessed" from any Nydus Warren or other canal. After being loaded with units, it can also transform back into a Nydus Worm for transport.

The Nydus Worm works like a Ghost nuke; the player places a beacon, and a few seconds later the Nydus Worm pops up.

The Nydus Wrom is treated as an armored unit.

Overseer
The Overseer is a Zerg unit evolved from the Overlord.

The mutation gives it the ability to detect cloaked and burrowed units, along with an increased sight range. However, it loses the Overlord's Creep and Slime abilities.

The Overseer's sight radius expands when it stays stills and shrinks when it moves.

Roach
Has a fast regeneration rate.

Additional Notes

The Roach is a very fast moving unit with 90 hp which recovers health quickly. One-on-one, a Roach will generally win in a fight against its enemies, as it regenerates health faster than damage can be delivered when it burrows. As such, sustained damage is required to effectively kill it.

Dustin Browder has confirmed that the roach has a melee attack. A bug in the game showed it as a ranged unit.

It is considered an armored unit.

A Roach Den is required for it to be spawned.

Swarm Guardian
The Swarm Guardian functions much like the original Guardian, though can also create Broodlings.

The Swarm Guardian is considered an armored unit.