A research base located in the northern part of the surface was seized by Raptures and modified into a giant Rapture.
It appears to be an ordinary building but transforms into its defensive form when hostile forces are attacking it.
Its true structure is reminiscent of a turtle with a thick shell and has formidable defensive capabilities that match its appearance.
Due to its size, it lacks mobility, but it uses several built-in armories to completely offset this disadvantage. 
Those dealing with the Land Eater feel hopeless when facing this insurmountable fortress.

Widely known as “Whale”, a large transporter for Raptures.
It is always visible during the Raptures' large-scale movements or raids, and its overwhelming size is enough to make a gigantic hole on the surface.
As it can store 1 large-scale Rapture inside, whenever Queen Whale appears, it is almost sure to change the tide of battle. 
It generates a unique wavelength, similar to the ultrasound of a whale, calling out nearby Raptures.
It doesn't have much in the way of offense, but with its huge transportation capabilities, it becomes a frightful adversary.
It is a very old model and has been in operation since the 1st Rapture Invasion.

Since humanity descended underground, the first attempt at reclamation was to dominate the surface's sky.
This is because it was determined that if an altitude unaffected by the anti-aircraft firearms of Raptures was secured, it would become easier to track and plan out actions.
However, that attempt was short-lived.
Due to the Storm Bringer, a Rapture that dominates the air.
Storm Bringer, with the appearance of a giant bird, quickly seized air supremacy among all Raptures, and has reigned as a peerless King of the Sky. 
Whenever the Ark has attempted to build a giant transport plane, it appears out of nowhere leaving destruction in its wake. It is the direct cause of the Ark's inability to develop any kind of substantial aviation.
Preparations can't even be made as it is constantly spewing magnetic fields and all kinds of disruptive waves.
It is a monster that always attacks in a storm.

A tank produced on the outskirts of the Ark by Outer Rim's outlaws, the radical armed group Heavenly Ascension.
It was designed to raid trains transporting supplies within the Ark.
Because it was built by gathering all the resources and skills of Heavenly Ascension, the technology itself isn't exceptional. But since it was handcrafted one by one by skilled craftsmen, it is nevertheless extremely well designed. 
Outrageously, it was discovered by the Central Government and seized before it could see the light of day under Heavenly Ascension.
Even from the Central Government's point of view, it was hard to justify using it as in spite of being well crafted, the level of technology was considered so outdated that it was deemed unworthy of operation.
It was eventually released and left unattended to on the surface, and it became a good target for Raptures.
After a little time, Alexander became a product of Rapture used to threaten Nikkes up on the surface.

A giant Rapture located on the surface, in search of the Ark.
It has a long body capable of free movement, and the ability to excavate due to the drill on its head which can pierce through the land instantly.
The existence of over a dozen Grave Diggers have been confirmed so far, as they roam the surface in search of the Ark.
Because it has a unique vibration pattern, it is relatively easy to notice when it is approaching, and it has a reputation for being the easiest to shoot down out of all giant Raptures because its power drops when dragged up to the surface using explosives.
However, this is only the case when it is fully exposed. 
Grave Digger's rushing and crushing power in an enclosed space is a nightmare.

Widely known as “Spider”, a giant Rapture specializing in ambush. 
Normally, it hides underground and attacks those on the surface when it detects large-scale Nikkes passing by. 
When stationed underground, all functions except the Nikke detection function are turned off, and its radar will not scan for humans. 
Much like its widely known name, it has the appearance of a spider and actively attacks with its long legs.