The swarm guardian functioned much like the original guardian as a siege unit, possessing a long range attack.
They look like a mutalisk laid out flat with its tail section behind it. Their bodies are made up of a total of five individual sections. The front section consists of the head and multiple appendages, maintaining the general appearance of the original crab-like guardian. There are three middle sections similar to the three rib-like claws that appear on the midsection of the mutalisk. Lastly a tail section which has four small spikes pointing backwards like those at the end of the mutalisk's tail. They move with a breaststroke-like swimming motion through the air. They are also much larger than their original counterparts, being only slightly smaller than a battlecruiser.
When a swarm guardian attacked, it produced broodlings which lasted only a few seconds. The broodlings are very weak but a large number could be quickly created, forcing an enemy to retreat. They spawned when buildings were attacked as well.
↑ 14.014.1The Swarm Guardian is similar to the original Guardian, acting as a flying long range siege unit. In addition, the attacks also spawn Broodlings upon hitting the target, which do additional damage to the enemy, lasting only a few seconds. Karune. 2008-05-22. Re: guardians?Battle.net StarCraft II General Discussion Forum. Accessed 2008-05-22.
↑To clarify, the Guardian's attack does not add a DoT (Damage over time) on the targeted unit. The targeted unit will take damage from the attack and then two Broodlings will spawn adjacent to that targeted unit every time the Guardian attacks. Each Broodling acts as an independent unit, controllable, and killable. Over a few seconds, the Broodlings will die on their own. With just a few Swarm Guardians, you can create an army of Broodlings upon your enemy in mere seconds. Nonetheless, these Broodlings do little damage and have little hit points - but with enough, it will definitely force your enemy to retreat. Karune. 2008-05-22. Re: guardians?Battle.net StarCraft II General Discussion Forum. Accessed 2008-05-22.
↑They spawned when the swarm guardian attacked buildings as well. Karune. 2008-05-22. Re: guardians? (page 2)Battle.net StarCraft II General Discussion Forum. Accessed 2008-05-22.