Baneling

The baneling is an explosive zerg strain, evolved from the zergling.

Overview
Banelings are created from zerglings following a brief chrysalis phase. In the new form, the zergling's claws shrivel and become withered, and a swollen sac filled with volatile chemicals grows out of its back. When a baneling gets close enough to an enemy, it triggers a reaction within its volatile chemical payload, causing the creature to explode with a shower of searing acid. The explosion destroys the baneling but also inflicts terrible damage to its enemies, highly effective against both structures and ground forces. In fact, a clutch of them is capable of wiping out a group of vehicles and infantry in the blink of an eye. The banelings' lethality is further enhanced by the zerg predilection for burrowing. An apparently safe area can soon turn into a deathtrap as these monstrosities emerge and roll into the midst of their foes, giving them virtually no time to react.

Due to their bloated nature, banelings are barely able to walk. They have been observed to tuck into a ball and roll.

History
Banelings were first observed in the Siege of Cask. Its defenders held out against the zerg long enough so that it came to pass that only minor breeds such as zerglings continued to be spawned to be sent into battle. However, queens drove the development of a new strain, via zerglings incorporating native mould into themselves. These new banelings were thus sent against Cask, their spray of acid destroying its defences and erradicating the terrans present. The data the Terran Dominion could have recovered was lost when one of the survivours destroyed it and herself in a rage against the Dominion for using the colony as a place to observe the zerg's adaptability. This data, and the wreck of the battlecruiser hosting it, wasn't recovered until 2507.

As such, when terrans encountered the baneling for the 'first time', they thought it was a mutation of a previously unknown genus rather than a morph of the zergling. The baneling was duly added to the list of threats and scientists began an effort to develop chemical rounds to detonate banelings prematurely.

Game Unit
Banelings are relatively small units that slowly move around the battlefield and kill opponents with a low-damage suicide attack.

Banelings do not roll unless they have their speed upgrade.

It is strong against s, s, and s. It is weak against thors, stalkers, and roaches.

Attacks
Banelings are strong against melee units and "light" buildings such as bunkers and photon cannons but are weak against ranged weapons due to their low hit points. They are designed to counter s, s, and un-upgraded s.

Groups of banelings do not attack individual targets with overkill, they will only detonate as many of themselves as needed to destroy one target before moving on to the next (or waiting for new orders). When assaulting multiple targets banelings can transition from a just-slain target to a still living one in a fraction of a second.

The baneling's splash attack does not injure friendly units. It does full damage within the splash radius.

If a baneling is killed, it explodes, dealing splash damage around it.

Banelings won't accidentally target buildings when ordered to attack units.

Strategies
Banelings are a powerful economy-raiding force; by using overlords to transport them into an enemy base, they can quickly devastate the workers. However, a planetary fortress is well suited to destroying the banelings. Use of raiding is recommended even until late game.

Banelings should be mixed with zerglings when facing ranged opponents because they become difficult to focus fire; even one baneling escaping the fire can destroy a mass of ranged units.

Banelings have low hit points so are best used in ambushes. They can burrow, attacking like mines, but can also attack from other hidden areas, such as behind trees, to accomplish the ambush.

Banelings are very useful against marines and zealots, even into the late game, and generally dominate units such as zerglings in combat, but zerglings can come out ahead with micro. Banelings can be defeated by marines equipped with stimpacks or defended by marauders.

As they do splash damage, banelings are effective against cloaked units. For instance, a group of dark templar attacking a hatchery can be eliminated by banelings that target the hatchery itself, or by commanding the baneling to explode on the spot.

A baneling/roach combo can be very powerful against terrans. The roaches will soak incoming damage, making it easier for the banelings to reach their targets.

Baneling Development
As of April 2008, banelings have been increased in size from previous builds to make it easier to focus fire on them. In addition their splash radius was increased. The supply cost was higher.