SWARM is an acronym. Death mentioned the real name for the SWARM when he opened the wormhole that had the armada flood into the Doctor's universe. Their full name is "Sentient Warfare Articulated Robot Machine".
The name refers to the general purpose of the machine not the effects. It hlds some artificial intelligence, and is clearly for conquest/invasion or warfare. The name 'SWARM' became commonplace with the Time Tyrants.
SWARMs go into a kind of 'temporal hyperspeed' when they travelled through time. This caused them to propel themselves forwards before vanishing in a small plasma explosion, before reappearing in their destination within the same plasma explosion followed by the SWARM emerging.
With normal space travel, the 'regular hyperspeed' function works the same without travelling to a distinctly different pint in time and/or space. They can also fly at normal spacecraft speeds for light travel.
During flight, the SWARM makes an ethereal and harrowing whirring noise that is almost similar to a choir singing one note. This was apparently an accident but it manages to invoke fear into planets because they register what is coming once they hear it. However, it is shown that the SWARM can fly silently (though this is probably reserved for infiltration units).
Unlike a TARDIS which creates strong wind and slight tremors upon arrival, a SWARM is completely silent and almost unnoticable, merely appearing and hovering upon arrival, making absolutely no real movement to the environment.
There are two types of SWARMs used by the Time Tyrants. Both are very similar but have distinct differences in design.
Infiltration SWARMs are much smaller and quieter than Attack SWARMs. They do not make the whirring noise when in flight and they come with a cloaking device, making them able to scower a planet or station without being noticed.
They are also much faster, helping with a steady and quick retreat. As opposed to Attack SWARMs which are bulkier and slower.
The Surgeon's SWARM is shown to be an infiltration SWARM.
Attack SWARMs are larger and heavier without as many stealth defences as the infiltration models but pack far more firepower. They also carry a polarity shield that deflects most energy weapons, allowing bombardement to be easier and quicker.
They are slower because of all the armour and weapons but make up for it with the ability to destroy enemy targets much quicker. Attack SWARMs also have the whirring noise but it can apparently be switched off for surprise attacks.
The armada sent to Earth were all Attack SWARMs.
Features and functions
There are many basic features and weapons to both types of SWARM.
A SWARM, like a TARDIS is shown to be bigger on the inside than the outside. The Time Tyrnats mention that it is 'smaller on the outside', as the exterior of a SWARM is actually shrunk down to make it more compact for warfare.
Compact mode means that the SWARM's exterior can go even smaller that it will fit into a Tyrant's hand or pocket. This is if the Tyrant wishes to enter another SWARM or space-time vessel and not let his SWARM be invaded. While transmatting to the vessel, the SWARM will simultaniously shrink for the Tyrant to have in their hand to keep a hold of.
The Tyrant can then use the transmat device again to reverse the process and end up back inside the SWARM fully-sized again.
The common weapon used by the SWARM, it fires stored kinetic energy which becomes highly explosive when fired and causes heavy damage to anything hit by them. These are typically used to eliminate enemy troops.
A Star Bomb is a small but deadly weapon that is apparently 10x as powerful as a hydrogen bomb. Once thrown onto a planet, it will caused irreverable damage and will destroy a radius larger than that of 10 million Asias.
Time Tyrants normally use these on planets they actually deem a threat to their empire.
Before their temporal technology was shut down, Time Cannons were used heavily. They send a blast of pure time energy that speeds up the ageing of organics and their machinery. Ships hit by it rust into nothing in seconds with the crew wittled down to mere bones along with it.
The Time Cannon was considered their most feared weapon, but because of the effects of the Time War, they were no longer able to use them.
Like TARDISes, SWARMs could blend into the environment of any planet at any time using this defence mechanism. Both types use it and can become anything from a rock to a whole temple.
The S in SWARM means that they are in fact sentient so it would mean that SWARMs, like TARDISes are self-aware. They seem to be able to fly without even the need for a pilot but they seem to 'prefer' having a pilot.
Judging by the harsh circumstances of the Time Tyrant lifestyle, the sentient mind of a SWARM would be incredibly hostile and sadistic, however they would still be submissive to any pilot's commands, even that of the pacifist Surgeon.
A wormhole deployer is used only once as there can only ever be one charge in a SWARM that will create a wormhole. The deployer has the coordinates set for a specific dimension they wish to cross into and then ejects a small canister that creates a wormhole for a SWARM or maybe more SWARMs to pass through.
However, a planet or sun is needed as 'fuel' to create the wormhole's density, meaning the canister can only work if fired into the soil of a planet or burned up by the thermonuclear radiation of the star.
The Surgeon's SWARM
See main article
The Surgeon actually stole an infiltartion SWARM during a bombardement on a planet under Pestilence's orders. The Surgeon, sickened at the bioweaponry used on innocent people in first hand caused him to kill a fellow Tyrant and vanish with his SWARM. The Surgeon's SWARM is now both his transport and his home.
Some SWARMs are shown to be customised for certain individuals, such as the Horsemen.
The Comets are the Horsemen's own SWARMs. They are called the Comets because of their rather harrowing ability to merely fall into a planet and will continue falling without being destroyed and finally crash land completely unscathed, holding the death merchants within (except in Death's case - which instantly falls into 'compact mode' with him safely on land).
The White Comet is War's own personal SWARM. A huge white spearhead-shaped structure that seems to be made of rock or coral. It creates the largest crater upon impact with a planet.
When War landed on Earth, his SWARM lived up to its nickname by coming down slowly like a giant white glowing meteroite. It landed within the Amazon rainforest, completely unnoticed by anything as it would be lost within the forests. Inside it, held all the equipment and components needed for War to construct Famine's machine.
The Blue Comet is Famine's own SWARM. It creates this ominous blue light around it as it 'falls' to a planet. Its default form is that of a large, metallic blue orb with slight markings and holes in it, keeping a very simple design. This shows Famine's lack of artistic creativity as she has no imagination to create something that is not merely a geometric shape or simple and easy to operate blueprint.
Apparently, inside Famine's SWARM is nothing but one giant supercomputer and in the centre of all the processers and wiring is Famine in her 'throne' plugged into everything and controlling her entire SWARM, from its movement to its weapons merely by sitting there and thinking - plugged into the very mainframe.
The Red Comet is Pestilence's own personal SWARM. It is one of the most feared sights in their Universe, second only to Death's 'Gold Comet'.
It appears surrounded by a blazing red trail as it crashes to a planet. The look of the Comet appears as a cluster of spikes made of red crystal to form a sort of 'star' shape. The back is flat and presumably the entrance/exit.
As it flies across space, it spins like a drill, plowing through asteroids and minor planets as easy as a knife going through bread.
Within the Red Comet, is nothing but a small world of woe and misery, where the survivors of Pestilence's onslaughts are captured and kept there to suffer until they die. Nothing but more crystal, merged with the very mechanics of the SWARM as Pestilence roams his own little kingdom. The Surgeon likens it 'the closest thing possible in their universe to Hell'.
The Gold Comet is the most feared of all omens in the Time Tyrant universe. Merely seen as a yellow ball of fire, slithering through space before finally falling to a planet to destroy. From what is seen within the flames is apparently just a shadow. Reports of people who have seen it and lived usually come from babbling lunatics who have likened it to either a dense shadow, a skull, the face of a demon or even just the figure of Death himself.
The 'Gold Comet' does not crash into a planet. Instead, it creates a small sonic boom and a pulse of golden light before Death emerges from the faded light, with his SWARM apparently in his robes, in compact mode. This is a theory that most people hope is true.
Nothing is known about the interior of the Gold Comet and most people don't want to know.
- The name that the acronym creates ('SWARM') could be as a reference to how Attack SWARMs completely surround a planet like a wave of insects, like they did with Earth. (DW CS: Abandon All Hope)
- The SWARMs also look quite insectois in appearance, further emphasising on the swarm-like qualities they have.
- SWARMs, unlike TARDISes, are shown to have a 'default' exterior setting, unlike the TARDISes who are never shown what they really look like when not using a chameleon circuit.
- The SWARMs are vaguely simialr to the hive-mind army of drones that compose the villain Gah Lak Tus in the Ultimate Marvel Universe.