Symbiotic Legion

The Symbiotic Legion were a swarm of 3 meter high 'soldiers' that resided inside the egg cases on the body of the Legion Queen. The creature's real species name is not known, with the creatures been given the name 'Legion' after a soldier who witnesses them refers to them as Legion from reciting a bible verse.

(And Jesus asked him, "What is thy name?" He replied, "My name is Legion, for we are many." Mark 5:9)

The creatures were controlled by their Queen using electromagnetic waves and would do her bidding for her - similar to how ants and bees work for and protect their Queen. In the times when she lost control over them or they could not eliminate a threat, the Queen herself would enter the fray.

The Queen could generate as many as 100 soldiers as once, with the creatures able to fly and are armed with sharp mandibles. They can also break down silica and convert it into oxygen - which is used in growing their Legion flower in order to continue the species' colonization of other worlds.

Information
The Legion Queen and her swarm first appeared on Earth by a meteor - which impacted in Japan, not far from Sapporo. As the Queen began to prepare their species' flower in order to restart the colonization process, the symbiotic legion soldiers went to work in finding silica to convert to oxygen for their plant to grow. These searches for silica caught the attention of humanity, as fiber optic cables began to go missing while Sapporo suffered a large amount of electronic interference. The Symbiotic Legion made their first major appearance to humanity, however, as they attacked a brewery at night - converting the silica in the glass bottles. The worst, however, was when the creatures attacked a subway train - easily gaining access by converting the silica in the glass - before attacking any passenger carrying a transmitter of any kind such as cell phones. The JSDF managed to later rescue the surviving passengers, but a new threat loomed as the Legion's flower bloomed while the levels of oxygen in Sapporo continued to rise to dangerous levels.

It was soon realized that the flower is essentially a 'launch pad': the increased oxygen will aid the aliens in exploding the flower, catapulting its seed into space so that they can colonize yet another world. A greater danger was realized as it was predicted when the flower exploded, it would  destroy all of Sapporo - which could also happen if the military tried to destroy the flower themselves. Despite their attempts to destroy the plant's roots, the military failed, but a new hope soon presented itself as Gamera - a giant fire-breathing turtle created by the ancient civilization of Atlantis as a defender of all life on Earth - flew into the besieged city. Recognizing the alien plant as a threat, Gamera ripped the plant out from its roots, thus saving Sapporo and temporarily halting the Legion's colonization plan. However, Gamera soon found a new adversary as 100 Symbiotic Legions swarmed out from the ground and attacked the Guardian of the Universe, managing to bring down the giant turtle. However, the creatures abandoned their attack as they were attracted to a nearby transformer - been killed by its searing electricity. With the swarm defeated, an injured Gamera left the city - unaware of the horror that he had yet to deal with as the Legion Queen also departed from Sapporo.

Scientists recovered the corpses of the symbiotic legions, with the hope that examining the creatures would allow them to discover a weakness that could be exploited. As they learned more about the extraterrestrial creatures, scientists learned that the aliens were silicon-base organisms - with them using pressurized gas that passes through their exoskeleton as a way of moving instead of having muscles. Furthermore, they learned from the Symbiotic Legion's death that the creatures were attracted to high electromagnetic waves - with the realization that the creatures would be heading for Tokyo: the largest source of electromagnetism in the nation. The proof of this was confirmed when another flower later bloomed in Sendai, with the Legion Queen having escaped her apparent death at the hands of the JSDF (who had apparently shot her down over the ocean but with only one giant wing found). The military soon discovered that another swarm of the creatures had met their end on the power lines. As the military evacuated the area and Gamera headed towards Sendai to destroy the flower, the Legion Queen made her appearance - battling the heroic turtle and badly injuring him due to him holding back (as one helicopter of civilians was currently unable to take off). The Queen eventually triumphed over Gamera before taking her leave as the pod prepared to launch - only to become desperate as Gamera seemingly sacrificed himself to prevent the pod launching, although Sendai was destroyed as a result.

With Gamera apparently dead, the Self Defense Force is deployed to try and prevent the Legion Queen - herself determined to create another flower with her arch-nemesis now gone and only the military standing in her way in her route towards Tokyo. When the Queen appeared at the first line of defense, the military attacked her with a relentless and valiant assault, but the Queen's durability allowed her to withstand the attack before using her EM Beam to cause heavy losses to the military before she continued her advance. During her assault, she unleashed another swarm of her symbiotic soldier legions to fly on ahead and attack the other lines of defense. Unfortunately for the Queen, Gamera had been revived by Asagi ( a girl who shared a psychic bond with Gamera through a mystical jewel she owned) and a group of believers. Although Gamera's link with Asagi was lost as the jewel shattered, Gamera then proceeded to the Legion Queen's location as gunners on one of the defense lines opened fire on the airborne swarm, which split up to avoid the attack. As Gamera arrived and engaged his extraterrestrial adversary, the Queen sought to eliminate her foe quickly and called back her swarm.

Despite an attempt by one of the soldiers to convince his commander to assist Gamera, on the basis that Gamera wouldn't be able to fight both the Legion Queen and her swarm at once, the commander refused. Thankfully, a man inside one of the nearby power stations was convinced to turn on the station's transformers - with them powering up just in time to attract the swarm, with the Legion Queen loosing control over them and been forced to fight Gamera on her own. Although the majority of the creatures gathered on the wires, one creature got inside the building. Thankfully for the men inside, a soldier had arrived and managed to eventually kill the creature. Calling in air support, a group of military helicopters opened fire on the power station as the men got out - destroying the Swarm. Some time later - after a heated battle and with help from the military - Gamera would finally destroy the Legion Queen using his Mana blast, with the extraterrestrial threat finally conquered.

Appearances
Gamera 2: Advent of Legion - Movie

Gamera 3: Awakening of Iris - Mentioned/Stock Footage Only