The Mothership is a powerful warship deployed by the Ravagers in most of the EDF games, sometimes acting as the final boss.
As seen in 2017, the Motherships appear to be biomechanical lifeforms themselves, as the one hunted during this war was stated to be breathing and its shutdown analogised to falling asleep.
The Mothership of Monster Attack appears in the introduction to the first mission. It is a massive grey flying saucer with a yellowish underside, purple domes on the edges of the upper surface, and a series of spikes on its underside surrounded by a purple band, which are the vanes of its main weapon. The Mothership is destroyed in the last mission of the game, mission 25: Judgment.
Global Defence Force
The Global Defence Force Mothership is similar in appearance to the Monster Attack version, but is all-over grey. It first appears in the seventh mission, Invaders! and is destroyed in mission 34: Judgment Day. However, the war is far from over, as shortly after the defeat of the Mothership the vastly larger and more powerful Floating City Adan materialises and commences its own assault on the Earth.
Earth Defense Force 2017
The Mothership, now an enormous silver sphere, appears in the very first mission of the game, though it stays out of reach to the player for the vast majority of the game.
It is eventually destroyed during the game's final mission.
Earth Defense Force Insect Armageddon
Insect Armageddon's Mothership turns up during the last mission and is more or less just a set of guns Strike Force Lightning cannot do anything about as they try to escape from it. The IE Mothership is not spherical or saucer-shaped like the others, instead looking to be roughly triangular, and has a black exterior with a "biomechanical" look and glowing red highlights. It has spread guns and giant lasers, and routinely deploys both types of Hector from its underside.
Since Insect Armageddon's campaign appears to have been cut short for either budget or time reasons, there is no actual battle with the Mothership and it is never made clear what happens to it. If closure to the story is required, it could be assumed that it was destroyed when the "package" detonated.
EDF 2025 / 4.1
In Earth Defense Force 2025 and Earth Defense Force 4.1: The Shadow of New Despair, Motherships are first mentioned in mission 8: Retaliation. As the EDF focuses on exterminating Spiders that have emerged from the new giant insect nest, a fleet of ten Motherships is detected lifting off from the surface of the moon. In the next mission, Beach Fear, the EDF engages the approaching Ravagers with their increased space defenses, opening fire with the "Equator Linear Cannon" and Tempest ballistic missiles fired from warships and submarines. With the sensors of the Ravager fleet blinded by the heat flare of their atmospheric reentry, two Motherships are destroyed and two more crippled before they realise they are under attack and erect Shield Screens to ward off the remaining strikes.
The first Mothership makes planetfall over Japan in mission 10, The Return, escorted by six Transport Ships. The EDF focuses on eliminating remaining Ants first, until the Mothership unveils its Genocide Gun and opens fire. After this show of force it retreats, leaving Storm Team to fight a force of Flying Drones and more Ants deployed from its escorts.
The Motherships have soon deployed a substantial force of their own ground units as part of a new campaign to destroy the human race, including Drones and Hectors, and soon after their mighty Quadruped Fortresses. In mission 18: Artillery it is established they are also dropping a new type of support unit, the Shield Bearer, to support their ground units.
A first attempt to destroy the Mothership over Japan using ground forces in mission 32 (33 in 4.1) Thunder proves hopeless as the Mothership endlessly fires the Genocide Gun and its cannon panels at the city below, giving no chance to engage it. The EDF get their chance to destroy the Mothership menacing Japan (probably) in mission 36 (37 in 4.1) Starship. Here Storm Team must first destroy the Genocide Gun, then attack the Mothership's core while dealing with fire from first its cannon panels (a total of 62 panels, 40 firing lasers and 22 firing explosive plasma bolts) and Drones, and then a series of massive energy weapons it deploys from its underside as the situation becomes desperate. The Mothership finally falls and in the next mission it is revealed that three Motherships, in Japan, North America and Europe, were destroyed by the coordinated worldwide assault. However, the invasion is far from over.
In missions leading up to 41 (43 in 4.1) Annihilation there is talk of some new Ravager weapon appearing across the world and destroying EDF bases, and it soon becomes clear that the Mothership fleet was only a prelude to the true might of the Ravagers as they deploy their trump card, the Earth Eaters. Motherships are not mentioned again until the final mission.
A last Mothership is mentioned in the final mission, Star Eaters, if the mission goes on for long enough. It is said to be approaching the area where the EDF is having their final showdown with the Ravager Brain, and HQ states that there's no way for Storm Team to fight the Brain and a Mothership at the same time. Luckily, some forces remaining in the destroyed EDF field headquarters succeed in activating the satellite cannon Nothung, destroying the approaching Mothership with an overload shot that also permanently disables the satellite.
Another Mothership which was said to be in orbit before (and therefore is presumably one of the two not destroyed or damaged during the normal campaign, or a damaged one that repaired itself) is encountered in the mission Ship of Dragons at the end of DLC 2 in 2025 and the end of DLC 1 in 4.1. This Mothership carries Dragons in its hangar bays, but otherwise is fought in the same way as the one encountered in Starship.
Earth Defense Force 5
Several large Ravager vessels which may be the game's Mothership-equivalent have been seen in promotional materials for Earth Defense Force 5. The 2017 / 2025 / 4.1 spherical Mothership has not been seen, and these are probably intended to replace it.
The first is an enormous vessel with articulated drill-tipped structures resembling legs and a host of projections that look to be the barrels of weapons, implying this to be a combat-focused vessel. It is seen at the end of the reveal trailer rising threateningly over a group of EDF soldiers, further implying it is some kind of large threat within the storyline.
The second is a green-gold vessel resembling a smaller version of the Floating City Adan from Global Defence Force. These vessels, of which there are said to be at least twelve, are referred to as the "Immigrant Ships" in Japanese PR materials (expect this name to change in translation) and have been shown deploying Landing Ships over a city the EDF is defending. Since one of the alien enemies is confirmed to be called the Colonist, it appears these vessels are the invasion's colony ships, implying this time the Ravagers are invading to colonise the Earth rather than just because they can as is more normal for them.
- In EDF 2025, while the Mothership itself is indestructible before Starship, the Genocide Gun is not and can be destroyed any time it is deployed, having its normal health for the current difficulty. If it is, the Mothership will instead deploy its core any time the Genocide Gun is supposed to come out, but like Transport Ships in early missions, the core will show damage effects but not take damage. In 4.1 the Genocide Gun is indestructible before Starship, though the cannon panels can still be destroyed in Thunder when they are deployed.
- The Mothership's main weapon seems to always have been called the Genocide Gun in Japanese versions of the games, but the term was first used in an English translation in Global Defence Force, which called the Floating City Adan's main weapon the "Genocide Cannon" in the briefing for mission 68. The first time it was called such in a game released in North America was in EDF 2025: in 2017 it was just "the cannon."