Mugann

Mugann, a name meaning faceless, are simulated weapons the Anti-Spirals deploy in the opening move of their campaign against any race that has mastered Spiral Power. Once a world's Spiral-capable population climbs past a set threshold, an awakened Messenger calls the Mugann into being to purge that species, or at minimum to keep it occupied while other extermination methods run their course.

Three distinct forms appear across the story. The Soldier Class is the standard unit, orange with white trim and threads of pink energy, thrown at humanity in vast waves. The Jokyu-Mugann is a larger black-and-green command variant that organizes and directs the Soldier units. The biggest are Kyo-Mugann, tall and blue, and Kuu-Mugann, broad and purple, a pair that break into fragments and swarm a target from every angle; the two can also merge into a single spinning form, the Kuu-Kyo-Mugann, that rams enemies by rotating like a top.

Every Mugann carries a nearly unbreakable energy barrier that turns aside bullets and solid ordnance, plus lasers that annihilate whatever they strike. Their unstable molecular makeup lets them teleport across great distances, and it also means a killing blow does not simply shut them down; instead the wreckage converts into a bomb powerful enough to level everything nearby, roughly matching the destruction the intact unit could deliver.

Gurren Lagann proved able to hold off their assault and bore through one with the Giga Drill Break on their first meeting. To beat them cleanly, Simon devised a way of soaking up a Mugann's own laser energy through Gurren Lagann and firing it all back at once, then having the Grapearl squad gun down each leftover explosive with their handguns before it could land. That approach grew risky against large swarms, so Leeron later engineered a method letting Grapearls both breach a Mugann's defenses and seal it inside a shield, neutralizing the machine and its bombs together. Once the fighting shifted into space, the explosives lost their bite, since there was little left for them to wreck and the crew could weather or trigger the blasts from a distance.

The Mugann operate without crews, guided instead by Nia Teppelin or the Anti-Spiral will. They first materialized out of empty air when Earth's human population hit one million, triggering the Human Extermination System, and Nia awakened as the Anti-Spiral Messenger in the same moment. Human forces coined the name Mugann because these machines lacked the faces that marked Gunmen and Grapearls.

Beyond striking Kamina City, a huge Mugann force massed in orbit to ambush humanity's evacuation aboard the Arc-Gurren, but Gurren Lagann shattered most of the Soldiers, joined with the Arc-Gurren, and destroyed the combined Great Cage form. The assault on Kamina City ceased once Nia was pulled back to the enemy. Notably, the Mugann are the only mecha in the series rendered with 3D animation, aside from a couple of brief shots of the Dai-Gunzan's catapult arms, and the giant units are assigned genders, with Kyo-Mugann female and Kuu-Mugann male.