Swarm Creepers are specialized Creeplings.
Swarm Creepers, like their core genus, do not tuck into a tight ball and roll around the battlefield, but instead scurry swiftly due to their re-purposed anatomy. Swarm Creepers possess leathery wings and may swarm in out of nowhere to attack, hence the name. The creature triggers a reaction within its psionic chemical payload that causes it to "merge" with Creep in order to defend itself and augment its physical regeneration.
These psychically reactive creatures are highly effective against both air and ground forces; in fact, a clutch of them is capable of wiping out a group of vehicles and infantry surprisingly fast. The Swarm Creepers' 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 shower the unsuspecting enemies with a psionically neutralizing liquid, giving them virtually no time to react.
The Swarm Creeper is descended from the Creepling, created through the advanced ability of the Naiadi to manipulate their offspring. The Naiads have engineered a morph that use cosmic energies alter its material state.