Heart of the Swarm adds two new Zerg units: The Viper and the Swarm Host.The Viper looks like a giant dragonfly. It requires a Spawning Pool, an Infestation Pit and eventually a Hive. It has some fun utility abilities:
Consume allows it to consume 200 life of a friendly building over 20 sec to convert into 50 energy. That’s a nice battery recharger.
The Abduct ability costs 75 energy and let’s the Viper pull a friendly or enemy unit to the Viper’s location. Basically, a harpoon-like tongue that pulls long-range units into your Hydralisks or melee/anti-air units’ range. It could also remove your own units from sure death if you use it strategically. Let’s say an expensive Ultralisk goes in to do damage, and you pull it out of harm’s way before it gets killed so that it regenerates back home for later use.
Blinding Cloud creates a cloud for 10 sec that reduces attack range of biological and mechanical units under it to melee range. It has strategic use against enemy Marines, Marauders, Hydralisks, Roaches, Siege Tanks, High Templars and other range-attack units.
Check out the links below to learn more.