StarCraft II: Heart of the Swarm/New Zerg units

Swarm host
This unit will not need burrow upgrade to burrow and once burrowed it attacks its foes nonstop. It is like a ground version of the Brood lord only it spawns locusts instead of broodlings.

Viper
New spellcaster unit that abduct units, drain the health of a Zerg structure to gain energy and makes a cloud that reduces ranged units attack to 1.

Campaign units
Overseers and Corruptors won't appear in the campaign.

Lurker
Does bonus damage to light units and splash damage in a straight line. Must burrow to attack.

Impaler
Does bonus damage to armored targets. Like Lurkers they must burrow to attack but they don't do splash damage.

Torrasque
A special strain of the Ultralisk that revives itself from the dead every time it dies.

Infestor
In the Campaign it can permanently mind control any unit. Use its ability to control units on strong enemies like Thors, Siege tanks, Banshees and Battlecruisers.

Hydralisk
Can be upgraded to move faster off creep.

Mutalisks
This unit now self heals itself pretty fast while out of battle.