Heart of the Swarm- Evolution Guide: Get Slimed

The baneling evolution mission begins with a quest to kill off a crystal-studded creature with, as Abathur explains, a ‘decentralized nervous system’.  For whatever reason, this allows the creature to spawn two smaller copies of itself when it dies- and this is what you need to gather DNA from.  Send your cluster of banelings against it to kill it- but Abathur will tell you that that is not enough material yet.  You will have to head further North and kill a ‘prime’ version of the creature- which not only splits in two, but its subdivisions split in two as well.  Once it is dead, your remaining banelings evaporate, making way for a new delivery of banelings from Abathur.  These ones have the genetic material ‘spun’ into them, which causes them to split on death as well (although it apparently does not matter if this death is from being attacked or willingly exploding on an enemy).  They will only split the one time, though so the mini-banelings will not further multiply.  You must then use these banelings to assault the Protoss forces lurking nearby.  Be aware that at least one cluster includes buildings, so you’ll want to toggle the ‘auto-attack buildings’ button while you’re directing the banelings.  Two additional deliveries of banelings will keep you in enough troops to handle the enemy forces here, so don’t get too worried.

The second portion of the mission involves banelings that, like the raptor-strain zerglings, have developed the ability to leap up and down cliffs and onto enemies- though in this case the ability stems from the need to avoid lava by climbing cliffs.  While this could be a lesson in an amusing and discredited alternate theory to evolution, the opportunity instead goes unnoticed in favor of the chance to assault a Terran Dominion base from behind and annihilate its SCVs and command center rather than get your banelings universally popped climbing up the slope in front of the base into a marauder/bunker defense.

Splitter banelings are remarkably useful for dealing with large enemy forces, partially overcoming the normal baneling difficulty that once you’ve popped them, they’re just gone.  While they don’t handle area-of-effect attacks any better than standard banelings, if you can use banelings effectively to begin with, this just makes them better- or worse, from your enemies’ perspective.  That said, it’s not terribly interesting and mostly just makes banelings more of the same.

Hunter banelings, by contrast, bring something different to the table- since they’re harder to splash-attack mid-pounce and the cliff-climbing grants them the raptor capability for off-angle assault, they can go a long way towards defeating the exact types of defenses that usually have a field day with anyone trying to use banelings normally.  It increases their chances of getting into explody death range drastically, particularly when they’re sent in on a different angle from what would normally be anticipated.  Hunters are also much easier to use in tandem with regular zerglings or other melee forces, as the leaping means they won’t be as obstructive or obstructible in combat.  Still, in situations where banelings are normally effective to begin with, they don’t really add much.