An Earth Eater is a modular part of a gigantic weapon system, said to be equivalent to a planet's mass, that the Ravagers deploy in Earth Defense Force 2025 and Earth Defense Force 4.1: The Shadow of New Despair following the destruction of most of their Motherships.
Earth Eater modules drop down vertically and connect together at their edges to form a continuous surface that covers the entire sky over their target. It is stated that as well as being heavily armed, the combined weapon also jams most communications and alters the climate beneath it, presumably to a form more appropriate for the Ravagers.
Earth Eaters are first mentioned in Waterside Bugs when they make their appearance over EDF bases in Sydney and Hawaii. Both are attacked and destroyed, with only confused messages about the areas being "swallowed whole" being relayed to command. Storm Team first encounters them in the next mission, Annihilation, where a routine assault in the mountains turns into a desperate battle for survival as an Earth Eater belt assembles overhead and Large Transport Ships appear for the first time.
The EDF attempts to take on the Earth Eaters assembling over Japan in Crazy Skies, but this proves to be futile; even when a huge hole is torn in the Earth Eater belt and the remainder vanishes, more modules descend and form a completely new one. Storm Team is ordered to retreat while the EDF rethinks its tactics.
Eventually, Ohara essentially guesses that the whole system must have a command module which he dubs the Brain, that coordinates the actions of the other modules. Luckily this baseless supposition proves to be entirely correct, and an examination of recent meteor impact craters eventually uncovers the Brain, a colossal tower-like module. An EDF attack on the Brain initially succeeds, but it flees the combat area before it can be destroyed.
The EDF finally confronts the Brain in the mission Star Eaters, and for reasons best known to itself it chooses to stand and fight this time, summoning hitherto-unseen Earth Eater variants as it becomes increasingly desperate. However, it eventually falls to Storm Team, and with its destruction the threat of the Earth Eaters is ended and the remnants of the Ravager fleet beat a hasty retreat.
The basic module is a simple hexagon with a flat lower surface. It is indestructible unless it is assigned to a Core module, and harmless unless it has weapon installations. If it does, these can be destroyed individually.
There are three types of weapon installation a basic module can have: the blue dome-shaped weapons fire a powerful green laser similar to the attack of the Mothership's laser cannon panels, while the fork-like purple weapons fire white glowing plasma balls. The red weapons are more dangerous, firing a glowing red plasma ball which has splash damage and can destroy buildings, rather like the "artillery" panels of the Mothership.
If these weapons are destroyed normally they have a chance of dropping one item each, like standard enemies.
The hangar module is a standard (though very large) spawner unit that generally deploys either Flight Vehicles or Deroys. Like a Transport Ship, it is vulnerable when it is open, and can be destroyed in any level it appears in.
The cannon module is shaped like an inverted hexagonal pyramid, and occasionally opens to fire a giant beam straight down, revealing its glowing blue interior. This is vulnerable to attack, and the cannon module can be destroyed independently of others. In 2025 being struck by fire from a cannon module was instant death, while in 4.1 it deals a set amount of damage.
Core modules appear more rarely than others. They have a concave lower surface with a glowing orange-red core similar to a Mothership's core inside. They are said to be control nodes, and in gameplay terms this means that if one of these modules is destroyed, all of the modules around it are destroyed too. It should be noted that this works like destroying a Deroy's body before its legs, however; if the surrounding Earth Eaters include armed basic modules, none of their weapon installations will drop items if they are destroyed by the destruction of their assigned Core.
These modules are only encountered in the second phase of the missions Star Eaters and Starry Prison. They are basic modules with a "step" in their lower surface. They mount the same weaponry as the standard Earth Eaters, though they always have more weapon installations than standard ones, with the addition that they can also mount a large green cannon which fires powerful continuous purple laser beams.
These modules only appear in the final stage of the missions Star Eaters and Starry Prison. They are about three times taller than standard Earth Eaters and resemble the core of the Brain. They lack the indestructible armor of the previous types, and can be damaged by shooting any point on them, but are simultaneously Hangar and Basic modules. They have powerful new attacks, shooting out huge arcs of lightning or giant red energy balls which create a devastating explosion on impact (similar to the main attack of the Mothership in Global Defence Force), though the latter can actually be deflected by shooting them. They also deploy waves of Dragons.
Main article: Brain
The focal point of the whole system is this skyscraper-sized module, said to be the only thing with the processing power necessary to coordinate so many individual units. It features the same invincible armor on its lower section, but a flower-like upper section which glows red and is vulnerable to attack.
Earth Defense Force 4.1
Earth Eaters fill the same capacity as they filled in 2025, but they are shown with a small difference; basic Earth Eaters now have a glowing green border rather than no glow at all.
- The Earth Eaters and the Brain are almost certainly inspired by the Floating City Adan, a giant Ravager warship that appears after the Mothership is defeated in Global Defence Force.