GUN (Guardian Units of Nations) is a group in Sonic Speed and a worldwide military and law enforcement organization. Run by a man only known as Commander, GUN seeks to protect the earth from all sorts of threats including Dr. Eggman. GUN has vast resources including an army of soldiers and peacekeepers, fighter planes and other instruments of warfare.
The GUN organization were responsible for the mistaken capture of Sonic the Hedgehog, the ending of Project Shadow, the invasion and subsequent deactivation of the Space Colony ARK and the deaths of it's inhabitants including Maria Robotnik. GUN attempts to contain the threat posed by Shadow the Hedgehog and Dr. Eggman. They send in a government spy, Rouge the Bat, to spy on Eggman and Shadow, and to retrieve information on Project Shadow via the ARK's database. However, they also attack Sonic and his friends. This proved to be have caused more harm than good in general although, unintentional.
GUN repel the invasion of Earth by the forces of the Black Arms by any means necessary including assistance from Sonic and his friends. Earth begins to be overrun, with GUN's forces almost helpless as well as carrying out the investigation and attempted destructions of Shadow. Their attempts at doing this are caused by the Commander of GUN due to his personal hatred of Shadow, although he realizes that Shadow isn't evil and it was simply a misunderstanding.
Shadow has now become an agent for GUN, whom they requisition to find Rouge as she has been presumably kidnapped by Eggman and being held at his base in White Acropolis. GUN are occasionally contacted by Shadow and Rouge for various purposes.
During their adventures, Sonic and Blaze infiltrate several of GUN's battleships and also blasts through their robotic forces. It is revealed that both Dr. Eggman and Eggman Nega combined their efforts to take control of the GUN forces present including their battleships and robots in an attempt to stop their enemies.
As Central City returns as a section for Sonic to revisit and restore in the White Space, many different GUN robots and also a GUN truck, reappears like the events before with Sonic escaping the military pursuit.
- Commander: An efficient officer, never backing down in the face of danger and commands his forces against Dr. Eggman as well as any other enemies. He is also responsible for controlling the Diablon robot.
- Shadow the Hedgehog: Shadow became a GUN agent after recovering his past.
- Rouge the Bat: Rouge has been a GUN agent for a very long time, being one of the organization's most valuable members and is high ranked, taking orders from the President himself and she works mainly as a spy.
- E-123 Omega: Omega joins GUN around the same time as Shadow did.
Foot soldiers of GUN armed with combat knives and a variety of firearms. They mostly wear black and blue, but they also have green, tan, black and brown camouflage clothes for jungle areas and commonly armed with pistols, machine guns and over-shoulder explosives. Some are also equipped with riot shields to protect them from frontal attacks.
Saucer-shaped one-eyed robots that float and they are variations. Some are armed with projectile guns, Rocket Beetles are armed with rocket launchers, Bomb Beetles constantly drop bombs, Spark Beetles have electrical shields, others with wings that allow them to move around and golden Beetles that are more armored.
Hunters are tall white humanoid robots armed with projectile guns. The Shield Hunter variations are equipped with large powerful shields and can use either guns or lasers.
Rhinos are blocky tank-like robots that may attempt to ram into their enemies however some are armed with either cannons, spikes on top for protection against aerial attacks or thickly armored.
Hawks are large floating robots and have two cylinder-shaped engines that are used to hover and manuever in the air. Different Hawks have a variety of functions including capable of firing projectiles, shooting lasers or dropping bombs.
Hornets are flying eye-like robots with several appendages that hold bombs and they fire them bombs towards their enemies as well as capable of firing lasers.
Artificial Chaos Series
Artificial Chaos are robotic versions of Chaos and can fire lasers from their eyes as well as extend their arms to battle in hand-to-hand combat. They can also float in the air as an orb of water and split into small cells to attack enemies.
- GUN Trooper: Green robots with red markings armed with semi-automatic rifles.
- Giga Trooper: Heavily armored, camouflage-colored robots armed with gatling guns.
- Blue Eagle: Bomber jetplanes that can drop bomb showers and feet can form into the Hunter robots.
- Fighter Jet: White fighter jets with a red nose-cone and has a cockpit with tinted glass. It has a single stabilizer at the back in white, yellow and red with a large flat section at the top of it. It fires off laser blasts and has four missiles that are separated in twos underneath each wing.
- Transport Helicopter: Large helicopters used mainly for transportation.
- Assault Helicopter: Military helicopters used mainly for supporting troops in combat.
- Truck: Huge trailers that are armed with saw blades and jet boosters for flight.
- Military Police Vehicle: Military police vehicles used by GUN personnel.
- Buggy: Basic military jeeps armed with missile launchers.
- HMMWV: Large, strong armored personnel carriers.
- Armored Transport Vehicle: Huge van-looking vehicles.
- Motorcycle: Military motorcycles armed with machine guns.
- Tank: Green military tanks equipped with powerful cannons.
- Aircraft Carrier: Several huge aircraft carriers that keep Blue Eagle planes on them.
- Warship: Equally huge ships sporting large cannons.
Big Foots are large bipedal walkers that can hover in the air and are manned by GUN pilots. They are colored in teal, yellow and red or a camouflaged color. They are strongly armored units equipped with gatling guns and missile launcher however some are armed with particle beam cannons.
- Flying Dog: Flying mechs that completely lack legs and are multipurpose fighters equipped with beam cannons, gatling guns, missile launchers and external stations can carry multiple conventional air-to-air and air-to-surface munitions and electronic countermeasure pods.
- Heavy Dog: Giant mechs that hover on the ground armed with a particle beam cannon and six circumferential homing rocket launchers.
- Blue Falcon: Large floating machines wielding a particle beam cannon and six circumferential homing rocket launchers.
- Diablon: A prototype energy-charged weapon and is a large red mecha. It is fitted with an electromagnetic barrier that deflects most projectiles and physical blows as well as a laser cannon secured on it's forehead and has a chargeable antimatter cannon. Diablon can also hover in the air by using jet boosters and has incredible strength and armor. However, it's weakness is that it is exposed while attacking as the barrier is shut down temporarily.
- Battleship: Huge, heavily armed battleships that can fly in the skies.
- Beetle Tank: Tank vehicles capable of operation on land or flight.
- Fort: Equipped with an arsenal of missiles and lasers.
- Gun Turret: Powerful gray machine gun turrets.
- Gun Lift: A powerful gun turret that runs on rail and is used for transport as well as being a hidden turret in case of emergency.
GUN's headquarters and is considered the most secure shelter on Earth. The underground fortress is heavily guarded by three mother computers, armed security cameras and an immeasurable number of GUN troops and mechs. It is located in a mountain near the sea within the United Federation.
A large jungle island used as a prison and research base by GUN as well as keeping Shadow the Hedgehog there before his release. However, Dr. Eggman, Shadow and Rouge the Bat attacked the island and planted explosives, destroying it.
- Knife: Combat knives are carried by many GUN troopers.
- Shield: Large bulletproof riot shields used by GUN troopers.
- Pistol: Semi-automatic pistols used by GUN soldiers.
- Sub-Machine Gun: Small submachine guns used by most GUN troopers and small robots.
- Assault Rifle: Large assault rifles used by GUN soldiers and robots.
- Gatling Gun: Fast-shooting powerful miniguns used by Big Foots.
- Heavy Machine Gun: Long powerful machine guns used as stationary cannons and robot weapons.
- Bazooka: Powerful weaponry that shoot explosive rockets straight forward utilized by GUN soldiers and robots.
- Grenade Launcher: Small, thick weapons that shoot explosive grenades that arch downward.
- Missile Launcher: Bazooka-like weaponry that uses lock-on technology to fire homing missiles.
- Laser Rifle: Guns that fire green lasers that bounce against any surface.
- Particle Beam Cannon: Powerful energy weapons that after charging up, fires multiple blue energy waves in all directions.
- Antimatter Cannon: Even stronger weapons that takes longer to charge and creates massive explosions.
- Gum Laser: Weapons that fire blue projectiles that stick to enemies, trapping them.
- Bomb: Spherical bombs that explode after a few seconds.